Of all those that have already been mentioned:
Mark Henry - Couldn't agree more. His character offers so much more but he always fails to deliver and is fast becoming oh so repetative. i liked his pairing with MVP as a tag team and thought that could have had some legs, but for whatever reason it didn't. He can't cut it as a singles performer in my opinion.
R-Truth - Yep, got to agree there too. I've never liked him as a performer. His showing during his match with Mason Ryan was horrendous, although that could equally be blamed on the Welshman's lack of in ring experience. However, with WWE being high on pushing newer talent at the moment, I think the more experienced Truth will suffer as a result, and rightly so in my opinion. As the more experienced performer it should have been his responsibility to look after Mason Ryan during his in ring debut.
JTG - No, don't agree there. I like his character. He has maintained what made Cryme Tyme so entertaining and carried it over into singles competition quite effectively. He is also showing a more competitive edge in recent weeks (well, the few bouts that I've managed to watch) and believe he will make the mid-card title challenger eventually, whether he wins a singles title or not will depend on his progress and fan following.
The Great Khali - A freak show and representative in the company for the Indian fan following. Nothing more. He is horrible in the ring. Period. Recent events in India may be used as an excuse to offload him and I won't be sad to see him go. Ranjin Singh will follow him out the door.
Ted Dibiase Jr and Cody Rhodes - I will be surprised to see either of these two go, but as someone else said there is normally one or two surprises in the clear out. They have failed to shine as singles stars, but collectively the could either re-invigorate a dissapearing tag division. Failing that, I think Cody will be the safer of the two. If that is the case then DiBiase needs to head a faction a la The Million Dollar Corporation.
David Hart Smith and Tyson Kidd - Again, both have stuttered in singles competition. Both are talented in ring performers, but have no personality. Collectively they are dynamite. A no nonsense, all about business in the ring, type of team. Come on WWE, admit you messed up and do the right thing.
Darren Young - I'm undecided here, but will say he will go. I think he has the want and desire to eventually make something of himself (shock!). But with the impatience of the WWE in making stars, I wonder whether they will persevere or just get rid, let him go elsewhere and develop, then bring him back in at a later date. Maybe that's what he needs. Look at The Rock, he wasn't initially well received when he was shoved down our throats as Rocky Maivia.
Yoshi Tatsu - The only link with the Japanese market at the moment. So I'll bet he is safe. Might not progress any further on the card, but he is safe nonetheless.
The Nexus/The Corre - Otunga, Slater, Harris, McGillicutty, Jackson (yes, I said Ezekiel Jackson), could all be under scrutiny and are my favourites for the chop if the members of these two factions are considered. It all depends on the progression of this and the mystery GM storylines methinks. Although I would like to see Trevor Murdoch return and team with Husky Harris!
Primo - Unless their is a resurrection in the Cruiserweight division and he is needed to make up the numbers in the short term, I see no future for this man.
Trent Baretta - I struggle to see where he fits into the bigger picture since the release of Caylen Croft and can only see him surviving under one of two circumstances. The resurrection of the Cruiserweight division as detailed under Primo...and a new tag team pairing of him and Joey Mercury. I see Joey Mercury going too, unless they have something lined up for him.
Curt Hawkins - I like his new attitude, but think he better suited at the moment as a tag team wrestler. Needs Zack Ryder back. They could keep their current personas. The relationship between the two is already documented, so would need no further explanation for their pairing. Would add a new dimension to the team, and strengthen that tag division again!
Jackson Andrews - Missed his short lived appearance on the main programming. But they must be high on him for them to try and push him so soon. But he could be on the list if he fails to improve.
Randy Orton - An interesting point raised by THTRobTaylor. But c'mon, really? No chance in Hell.
Christian - I can't see it to be honest. But never say never. I think with Edge's recent hint at retirement (was it a hint or just a mis-interpretation?) i think Christian will be heavily involved with Edge's last run and is therefore safe.
Jimmy and Jey Uso - Yep, I can see one or both of these young men being chopped. Unfortunately through no fault of their own.
Michael Cole - Safe and will become increasingly more annoying as a result! Shows he is doing a good job with his new direction.
Michael Tarver - Not yet established so could be on the wooden chopping block. However, there are rumours of a push for him. I think he stinks in the ring so lets just get rid.
Hornswoggle - In my personal wrestling preference biased opinion, he has long overstayed his welcome.
Tyler Reks - Has yet to step up from his attempted push and could be chopped unless the writers have anything for him. Shame, has some potential.
Chris Masters - I really his new persona. Needs to become more of a monster in the ring though. Would hate to see him go as I believe he has mid card title holder potential.
Vladimir Kozlov - It all depends on his team with Santino. Should that come to an abrupt end then I don't see where he would go in the grander scheme of things.
Chavo Guerrero - I can't see it. He will be retained, perhaps due to his affiliation with Eddie. He could be better used in my opinion, but if the company has nothing for him then who knows. Would shine in TNA if he was released.
Skip Sheffield - Nah, I'm thinking he's coming back into the Nexus fold as a replacement for Husky Harris.
My personal pics outside those mentioned:
Alex Riley - Good on the mic, but lacking in the ring in my opinion. Just a lackey to support Miz at the moment. Miz needs someone stronger behind him, like HBK with Sid or Diesel (I'm by no way making any comparison to Miz or HBK by saying that!)
Drew McIntyre - I know he is the chosen one or something like that. But he could be the surprise name on the chopping list.
Jack Swagger - Another shock candidate. Former World Heavyweight Champion to Superstars in a matter of months. A talented wrestler no doubt, but pish on the mic and has added no new dimensions to his in ring performance. Perhaps a wasted investment?
Divas - Just get rid of...The Bellas and Rosa Mendes. Perhaps alicia Fox too. The rest are relatively sound in the ring.