Hi
Another ex OFP and current Arma player here, though only got singleplayer on OFP and missed many of the later mods (real life kicked in there for a while).
From the info so far on Arma2 and the planned multicore support I believe the AI will feature much more prominently in single and coop games as it will get much more processing power. I'm not expecting huge leaps forward in other areas like graphics or map sizes, as these are about right currently (a few mins a in blackhawk in transit to an LZ is fine), but small things like not being able to step or jump over 12 inch fences should be addressed. With the wealth of addon maps, soldiers, civilians and vehicles currently available for Arma (not to mention mods like A.C.E.) being (reportedly) easily portable to the new system, I think for the PC community the game will hopefully attract back some of the players who left due to the instability of the early releases.
Now if they could fix it for small user defined missions (of the spawn-kill-die-repeat COD variety) to be downloaded and accessed by console players as well as PC players they could be onto a winner (did'nt OFP Elite on the Xbox allow something like that ?). Could open up the game to a console community bored with COD, or perhaps we want to leave the constantly sniping blighters where they are ?
Personally, I believe OFP2 has its work cut out both to compete with Arma2 at the sim end of the scale and COD at the arcade end, though I think arcade is probably where it will land, with a higher level of customisation. But then, thats what I hope for BF3.
cjph