An Atelier title is nice, sure, although I'd like to see more of the surge concerto series for now.
On the other hand, if the next Atelier series is RPG instead of SLG, then I'd be highly interested. It's been a long time since GUST last made a proper RPG (last one was At3 which was over 2 years ago...)
No no no no, we aren't even sure if the new announcement will be an Atelier title, let alone an Arland one. Besides, there has never been a GUST series/sub-series that goes beyond 3 installments, and however popular the Arland sub-series is, I doubt they'd break the pattern and extend it beyond a trilogy.
I just hope it's not another PS3 exclusive game, it would be nice if they put more focus on handheld consoles, I miss the 2D charm that the older games had. But more then anything, I think I'd rather see off shore releases of older titles.
Expensive PS3 + All of the PS3 exclusive Atelier games including Cross Edge and Trinity Universe = massive headache in the budget. If I were to buy a PS3 today at it's current price, I would have to wait until 2013 before I could buy a game for it; I'd much rather buy multiple games for the console I already have.