I am 99% positive a lot of the restrictions in the game are not caused by the PS2 limitations (i.e. memory).

And I think, even if you like the PS2 version, it'd be a better move for them to stop supporting it. Considering Sony don't even support the older PS2 models with the HDD. Most of the player base have gone to the PC or Xbox360, and I'll be damned if the rest don't switch over to PS3.

They'll most likely start slowly upgrading the game in bits, and you probably won't notice it. It's been happening for awhile with textures and coding.