Many of Peter's interviews has talked about a new IP that has yet to be named or shown.  But he has stated that it is revolutionary and ambitious.   The following Euro gamer interview brieflly talks about it at 15:20:42...

http://www.eurogamer.net/article.php?article_id=88581

I remember reading about Molyneux talking up a new IP. Hopefully he doesn't over promise. Not that Fable wasn't great because I love it, but it is sad when he says things you can do but they get cut from the game. I also wonder if we will see anything new from Rare that we haven't heard of. I mean they haven't done anything since VP have they? I thought they had a big enough studio to push out several games at one time? They had 2 launch games? I hope they have something super awesome and new next year along with BK3.

@ Adam540: Rare is also working on a new Perfect Dark, which is actually a sequel to the original (not a prequel) and retains the original's darker tone. Apparently, morality plays into it in a big ay. I forget what it is called, but it is 360-exclusive.

It's hard to get excited with Molyneux news - the guy is kind of hit and miss, he's always got those great concepts for his games but they don't always end up becoming a good game.

 Ah, yes! Me too!

well if they release all their sequel and announced one it's already a good line up... you have ninja gaiden 2, fable 2, gow 2, BK 3, alan wake, couple unamed project, halo war, probably some new IPs unheard of... and we can expect some 3rd parties to announce some revival of old IPs.... I'm still convince that what is to come will be even better than what is already there... MS has more or less settled it's RRoD problem, it is now making profit on each new units they sell, they have a great attach rate... they can pretty much focus on making games buying licences studios and exclu....and BTW is MS working on any XB games right now ??? is the new age of empire supose to come on XB or any other MSGS game devloped by them ?? like a motorcross madness or anything like that ??? or a new IP???
it could be nice to make a clear post with all rumored announced games exclu on XB

Molyneux mentioned it during an Internet chat session and it was also mentioned by a journalist who got a tour of Lionhead Studios when he was doing a preview of Fable 2.  I'll search for the links for both of them.

 Man could you imagine if they still have plenty more planned :P 2008 would be such a great year indeed. 

I actually haven't played any of Lionhead's other games :/ I played fable and B&W so I can just hope it's one of those XD 

I know they will bring out a new FPS game which uses thumbsticks to move and look around.

It's sure to do well the last 500 xbox and 1000 playstation games did surely this one will too.

Populous on the XBLA would be sweet. I'd buy it.