If you missed it in the TGS thread, Konami has released the MGS Peacewalker demo for everyone to try. You can grab it at
http://psp.ign.com/articles/102/1027904p1.html. Currently, there is no way to play this on CFW PSPs, to my knowledge. Definitely not on 5.00 M-33.
Brief impressions:
I hesitate to say this, because I don't want to give out the wrong impression, but this game to me is less like a portable MGS4 (in terms of game play) and more like Portable Ops DONE RIGHT. Everything has been greatly improved over Portable Ops. To compensate for the lack of a second analog stick, the default game play uses the Syphon Filter/Resistance PSP-style of control mapping. You use the analog nub to move around, and the face buttons work the camera. The R button works for both rolling and attacking, and the L button controls aiming/using weapons. Other actions are now on the d-pad, such as crouching (tapping down makes you go into sneaking mode; holding it makes you lay flat on the ground), Getting up against walls for cover is done by hitting up, as is taking items from fallen enemies (you have to be in sneak mode first, then you just hit up) Left and right on the d-pad serve to access your items/weapons, and you can cycle through them with the square and circle buttons. Finally, tapping select will enable auto aiming, so there will never be an issue with the shooting controls. (Free aiming is also available) There's also a completely different control scheme more akin to Portable Ops available, but the default settings all work great, and I had no trouble adjusting and taking out enemies. MGS3-style CQC is also in the game; you can also grab enemies and toss them into other enemies to knock them all out.
Although the game's presentation is like Portable Ops', in that you select missions from a menu and cinemas are presented in the same comic book style as before, there's also real-time cut scenes, and the visuals, animation, and general smoothness of the game play have been bumped up to a level approaching that of Metal Gear Solid 3. Everything just works much more smoothly in comparison to Portable Ops.
I've only just completed the first basic training mission. Missions are broken up into different areas, much like in MGS3. The mission select screen has room for four missions, but I don't know if there's more than two available in this demo. After the training mission, You can then play multiplayer (up to four players), and there are four different Snakes (with different outfits, each carrying different items and weapons) to pick from. Since it does list "Snake" under "character," this seems to be hinting that like Portable Ops, multiple characters will end up being playable. The game also has a ranking system, and even saves your game, so there's a lot here for a PSP demo.