It seems to me that there's only one way to ensure that naturalpoint trackIR will operate with games in the future: Someone need to sit down and design a standard interface for these kinds of devices. Any game that want to support the "free-lookaround" would implement the interface (including microsoft games). I got my trackIR last week and I absolutely love it in FS2002 & IL-2, I'm sure these devices are here to stay.
BTW, what's the news on Halo? Games on X-box typically allow look around with one of the analog sticks, and walk around using the other. Will this still be supported on the PC version? It seems most X-box games already have a trackIR dimension build in.
/ Stefan