Buy the MGS4 80gb console. This version comes with memory card readers (for flash cards, like those used in the PSP, phones, cameras), has four USB slots and it's got limited backwards compatibility with PS2 games.

The new 80gb is the 40gb model but with an 80gb hard drive. No PS2 compatibility, no memory card reader and only two USB slots.

Even if you don't like MGS4, trade it in or sell it, but you really want the MGS4 80gb over the new 80gb. In my opinion, any price difference between the MGS4 80gb and new 80gb is worth getting some PS2 compatibility and the extra hardware. Canada should get the new 80gb at the same time the US does, but the MGS4 version is worth the money