Saints row was a pile of crap, i tried really hard to like that game but it just wasnt happening. San Andreas was far superior in every way, the online play in Saints row was glitchy and had scaled down graphics that would have looked poor on the ps2. In single player campaign You were forced into doing the side missions in a lame attempt to pad out the game, and the plot was dismal.
Avoid the 360 and ps3 versions at all costs!!
Sources close to rockstar state rio is a "likely" setting for GTA4, rockstar have also stated a desire to pack detail into every nook and cranny of the city hinting that they may be going for detail over map size. I personally think its time GTA went M.M.O, what do you guys think?