Sounds like an awesome project.

I myself am getting a PI also, it is without the most AWESOME little thing that can be bought for that kind of money, i really hope that they make in the area of a million of them, no question that they are going to go as .... hard to even find the word there.

I myself am mostly focusing on just having a system on the PI, there are so many applications for it, gaming system (C64, DosBOX etc), media center.

But as a little add on for HDMI out for our N900 sounds very cool, and exchanging SD cards would be enough to go from that function to system on the PI.