The things needed on any platform are really good floating point performance, hardware accelerated 3D with full DX8 or OGL 1.3 support, at least 400meg of storage, 640x480 min resolution, plenty of memory. There is no longer a software renderer so hardware accelerated 3D is a must. The storage count comes from getting rid of all hi-res art and movies. You would need plenty of RAM or a complete revamp of the texture and bitmap systems to take images directly off of the disk (very slow since it has the read and process everytime). Scaling down to a lower resolution would be crappy and make most screens almost entirely unreadable.
Anthelion doesn't even compare since it was written from the start for PocketPC. Also the control system for the FS2 engine is based on mouse and joystick support. The io code would pretty much have to be entirely rewritten to work on a PDA.
So the chances of it being possible are slim but not zero. The amount of work needed to pull it off though would put the chances at less than zero. Of course that's really ignoring SCP code and working from the original Volition source release. You'd pretty much have to start there to get it done but it would still take a considerable amount of work.
