I think a Twilight was definitely a missed (so far) opportunity... I think an Attack Shuttle has a coolness to it though, and if Hasbro cranks out something nice (it's a fairly small/cramped craft it seems), I'm into it. I thinkk the Twilight's best hope was, as you said Jayson, the first season/launch of the line... Though I'd miss the AT-TE, knowing how awesome it is itself now.
Replace the TT with the Twilight, and I'm all for that ultimately, even though the Twilight's going to be grossly underscaled. It's just a better vehicle ultimately, but maybe Hasbro was more worried about how the AT-TE, AT-AT, TT, etc., have a central theme to them where you sort of play around them... The Falcon can have that too, but how much of the Falcon is also a collector/fan-wank? Plus the Falcon is practically the posterchild vehicle for the entire saga, at least to many.
Anyway, the AT-AT, AT-TE, and TT, all sort of have this almost "playset" feel... There's action going on around them that doesn't really require a kid holding onto another ship buzzing around, ya know? Of course, that doens't jive with the Attack Shuttle's playability unless you're considering the "downed shuttle" factor I guess.
Anyway, cool ship. Was neat to come back home and catch that when I got here.