IGN just wrote a hands on review of Syphon Filter: Dark Mirror. From all the screen shots I saw and the videos I wathced the game looks amazing. They described the controls as being pretty easy to use. Analog stick moves, vision modes are chosen using the left directional pad, the right directional pad allows you to pick weapons. The "X" button is basically the action botton.
The online play sounds great. Eight player Deathmatch, Team Deathmatch, Objective and Rogue Agent modes. From what it sounds like it's just like Socom, just with extra modes to play in.
This is a must buy for me.
http://psp.ign.com/articles/695/695160p1.html