There is no clear contender at welterweight at the moment.
Who makes the best case with a win?
#2 Condit va #10 Brown
#3 MacDonald vs #8 Lawler
#4 Maia vs # Shields
Condit winning would not be enough to warrant a rematch, Shields is out of the picture.
MacDonald stated he would never fight GSP.
If Brown or Lawler get KO/TKO or Maia submits Shields
Who would make the best case for a title shot?
Good question. It depends on method of victory; if Brown were to finish Condit it would unequivocally be him. Condit shouldn't get the rematch yet no matter what he does in that fight.
I honestly don't think Rory should get it with a win over Lawler (unless he wins super impressively). As good as Rory is, let's not forget his biggest win was that shitty, shitty fight against Ellenberger; and yes, beating Jake is bigger than beating an old, bloated LW. I think a finish over Rory, coupled with his finish over Kos, would be solid grounds for a Lawler title shot (if Brown loses or wins unconvincingly/boringly and Maia loses or wins by decision).
If Maia finishes Shields he should get the shot unless Brown finishes Condit or Lawler finishes Rory. A Maia finish win and a brown decision victory would be a toss-up for title shot imo. Even if Shields finishes Maia, I think he needs more wins to warrant that rematch.
If Brown, Lawler, and Maia should all win by either decision or finish I think priority should be given to Brown then Lawler then Maia. If they should all lose then it should be Rory.
If Condit, Rory, and Maia won I would argue for Maia (although it would be a toss-up between him and Rory MacDonald if the latter won by finish and the former won by decision).