I'm a bit divided on this. The first two were awesome, I loved them to bits. That the original is coming to XBLA is fantastic news alone.
As for the new game... I dunno. This whole building stuff thing sounds great in theory but I think depending on how integral it is will make or break the game for me. Much like Spore, while the concept and even application was fantastic to begin with, it reached a point where I was just like "ok, shit, I want to play the game now".
Of course, the building aspect could be the best thing ever and I might not be able to get enough.