Bayless only does one real NBA viable thing--getting to the line extremely well. Secondary things that are more replaceable are the fact that he can create shots at will for himself and can defend both guard positions decently at man-to-man situations, and that sort of makes him a decent backup player. But for a team that sorely needs a shot creator and a guy who can get to the line, Bayless might actually maximize his potential here. There will be a numbers crunch--Marcus Thornton, CJ Jerrells, Willie Green, and Belinelli will all split, and there will be some trouble as all of those guys sans Jerrells have gotten 15+ minutes in recent seasons, so that might be problematic.
But for those who really wanted Bayless in the past, he's just a replacement level player. Poor overall defender, combo-guard level passing, can be a out of control on drives, pretty poor long-range shooter. Just the driving game is really intriguing.