To be honest, I think a group like this has a MUCH better chance of getting over with the current audience than it did in the late 1990s. Now, before you jump all over me ("no way", "3 Count sucked then, they'd suck now too", "how do you pronounce your username, anyway?" - LOL!), hear me out!
The major problem with this angle (when it was originally done) was timing. Just like Slyfox already mentioned, WCW tried this angle when "boy bands" were at their hottest (I hate the term "boy band", almost as much as I hate the term "tweener"...*shudder*...to be a "band", you HAVE TO PLAY INSTRUMENTS!! they're all "boy choirs", not bands. /rant).
Yes, "boy choirs" (LOL) were popular at the time, but wrestling fans and boy-choir fans were two COMPLETELY different demographics. IE: WCW fans in the late 1990s were mostly males, aged 7-30 (roughly, right?)...your average n*sync fans were female, aged 7-30 (again, roughly). To put it simply - the average wrestling fan didn't own a Backstreet Boys CD, and the average fan of this music wasn't buying tickets for wrestling events.
With "3 Count", I think WCW was trying to create their own "2 Cool" (was it "Too Cool"? ...can't remember). When the WWE (WWF) had the idea to put 2 Cool on TV, they must have known that they would be booed out of the building. I mean, come on...two white guys dancing like idiots, and dressed like "club rats"? They must have known that 2 Cool would be heels in the minds of their current audience.
If you remember correctly, 2 Cool was initially HATED by the fans until Rikishi joined them. The only reason those two ever got over, was because Rikishi started dancing with them (Scotty's "worm" finishing move helped too, I guess). Although 2 Cool (w/ Rikishi) got over, it must have happened almost completely by accident (and to the surprise of WWF management). When 2 Cool became popular, I think WCW got the idea that they could also trap this mid-card lightning in a bottle (LOL!). Without someone like Rikishi to help 3 Count get over, it just didn't work with the current wrestling demographic (which, in the late 90's, was mostly older males).
The reason why I think an angle like this would work better today, is because the audience is younger than it was 10/15 years ago. Yes, there are some "older" fans that still boo Cena & Mysterio, but there are a lot more kids & women cheering for those two in a WWE audience today.
If WWE tried doing something similar (but not exactly like) 3 Count, it could work now (I'm not saying it DEFINITELY would, but I think it's got a fighting chance). For example, they could have a group of wrestlers that were like the cast of "Glee" - or "High School Musical". In fact, I don't really know why they haven't tried capitalizing on something like this yet. I mean, those ideas (Glee, High School Musical, American Idol, etc) are so popular with the younger demographic that it would just be smart business.
If it were up to me, I wouldn't put any "established" wrestlers in the group (like the wrestlers that were already mentioned by the OP); I think an angle like this would work better for some up-and-comers from FCW that we haven't seen on WWE television yet. Let them skip NXT (or whatever), and show up on Smackdown or Raw with a gimmick like this...or maybe test the waters in FCW first, to see what their audience thinks of an angle like this. Might be worth trying, at least.
I don't know exactly what the details would/should be for an angle like this, or whether or not the current fans would accept them as heel or face (at least initially), but I think an angle like this would definitely get some new guys over. Okay...(phew)...now that you've read my two cents, feel free to attack me for my opinion(s)! LOL!