The way I see it is there are 3 ways this could go; keep Kaz as Suicide but have him wrestle as Kaz sometimes, or vice versa; replace the man behind the mask (again); or Suicide leaves forever.
I'm glad Kaz has appeared as Kaz again, and personally I hope it stays this way. I prefer his in ring work without the mask. Although, I would be sad if Suicide was to disappear with no explaination, which is what I fear will happen. If they are getting rid of the Suicide character they should try to work it into storyline somehow and make a big deal out of it like Pedro suggested... but this is TNA we're on about, so I don't have any expectations there.
I believe the Suicide character had a lot of potential. There was a lot of build up to his debut... "whoissuicide.com" flashing up on our screens every week, the TNA game, then when I had almost given up the hope that Suicide would ever debut, he did just that! His debut was awesome; Kaz was as crisp as ever and pulled out a few stunning maneuvers!
Unfortunately I feel that neither Kaz nor Daniels pulled off the Suicide character as well as Kaz did that first time, and slowly but surely Suicide became, essentially, a jobber

Had Suicide been given a solid storyline maybe it wouldn't have gone that way...?
I think it would be great if TNA could find somebody who could fit the Suicide suit! Somebody who could be consistently as crisp as Kaz was when he debuted Suicide. Somebody who would be a worthy X Division opponent (not that Kaz isn't, he just isn't (or should that be wasn't?) as Suicide).