When Sin Cara was signed, WWE's developmental and talent relations system were under the control of Big Johnny, if I'm not mistaken. I think that while Triple H was ultimately responsible for bringing Sin Cara in, Triple H hadn't been an executive for very long and didn't have the sort of stroke he'd soon come to have as an executive. As we've all seen over the past couple of years, WWE's developmental system, now NXT, is universes ahead of where it was 4 or 5 years ago with Triple H in charge and, as a result, I'm more confident that things will work out for the best.
That's no guarantee, however, as there are pretty much no guarantees in real life or pro wrestling. Triple H, generally speaking, is much more of a wrestling than a "sports entertainment" type of guy and that's reflected in the changes he's made. That's not to say that some elements of "sports entertainment" don't wind up as part of NXT from time to time or that they won't wind up on Raw if/when Trips ultimately takes over from Vince.
Like others, my biggest concern is that they'll stick Kenta with some lousy, outdated Japanese stereotype. I know this sounds very simple, not particularly innovative, but I honestly wouldn't mind seeing Kenta's storyline being that he's ultimately come to WWE to prove something to not only WWE but American fans: smaller wrestlers are every bit the equal or superior to bigger ones. Kenta's billed at 5'8" and somewhere in the 180 to 185 pound range, which makes him one of the smallest men on the roster in terms of height & weight. Don't try to make him charming or funny, don't try to make him some sort of guy nobody takes seriously, but just as someone with an intense passion to compete and show what he's made of.
Off the top of my head, whether NXT or the main roster, the only one smaller than Kenta is Rey Mysterio. During his days in WCW, Mysterio was billed between 5'4" and 5'6" and about 145 pounds and in WWE, he's billed at 5'6" and 175 pounds. He's definitely heavier now than he was 12-15 years ago.