Screen by screen, the 3DS seems to have consistently higher detail but also seems to be more washed out ...
I do wonder how much of these negative points towards the 3DS are because of the capture mode (video camera vs. direct capture) or would seem different when playing in 3D. Part of my thinking is that one of the ways I notice the 3D on the 3DS is that images seem (somehow) brighter and more vibrant than a conventional 2D screen.
Looking through the screens it looks as if the geometry generally looks identical, but the texture quality and lighting varies greatly in the 3ds, such as the drop suit has clearly much higher resolution bump mapped texture than the ps2 and seems to have a higher polygon mesh, but other things look as if they have incomplete textures,if it releases in november that leaves a goodly amount of time to spruce up textures and lighting, if they choose to. if it is complete that is one haphazardly done port
regardless, snake eater is 30fps on ps2, and will be for all intents and purposes twice that on the 3ds, which is technically more impressive no matter what
plus lets face it, good looking ps2 games like mgs3 still look good, said games at twice the frame rate on the go would be good enough for me. though to be fair I think psp games generally look fine as well save for that obnoxious dithering so many games use, though I guess I'd take dithering over worse framerates (any peace walker screen without dithering is doctored)