The single most important feature I want to see in Flashpoint 2 is: maximum scaleability of performance.
The game should be designed from the ground up to work well on the average PC, not force you to buy a 3 Gigahertz Pentium 4 and Geforce FX card with 256 meg of onboard memory.
I have Flashpoint GOTY edition and, after a bit of tweaking, have gotten it to work fine on my system (850 MHz Athlon, 256Mb RAM, Radeon 7500), but it was a bit of a struggle - the autodetect feature in Preferences wasn't much of a help.
I really hope the developers play close attention to making sure that Flashpoint 2 can work smoothly with the average system of 2005, or whenever the game is released.