The UFC needs more welterweights?

Ok, I want to know what welterweight not currently in the UFC you would like to see in the UFC and name some middleweights both in the UFC and not in the UFC who you think could drop down to welterweight.Nick Diaz is set to take on GSP at UFC 137 and Nate Marquardt dropped to welterweight.Who else do you think will make a nice fit in the UFC's welterweight division?