Hmm...Kuma vs Kidd should be interesting indeed....
If Kuma is a cyborg, and Kidd can manipulate metal, then this could be a relatively easy win for Kidd. Considering that Kidd's bounty is higher than Luffy's, and Luffy defeated two shichibukai, it shouldn't be too outrageous for Kidd to be able to stand up to Kuma.
Edit: Also....rereading it....another possibility I consider is that Kuma is indeed the original captain of Law's crew. He does possess the same patterns that Law wears, and they both seem to be all about bears, too. Maybe there will be some sort of tie-in with this?