I think he'll play a little more next year (Probably around 10, MAYBE 15 minutes) Mostly because I don't expect Tony to be back, or at least remain in Boston for the full season. I still think he can be a really solid, surprising player. People doubted Powe, too and while I think Walker can surpass Powe in terms of NBA talent and especially scoring productivity, Powe had equal ciriticism regarding his knees and he's proved everyone wrong, so far (until the strain, which I forgot about while I was writing this)
As for the rest of the team next year, Erden would be a wasted spot, he's not good enough to contribute. We would probably have better luck trying to find a team who doesn't want their lottery pick and trading for that, And I hope that will actually become a legitimate option because I don't think both baby and Powe will be back next year so, and again, I think we have better chances of stealing Jordan Hill's draft rights via trade than we do bringing Erden over, or keeping Powe and Davis
And, finally... even if we do repeat this year, I won't feel confident walking into the season with that lineup. At that point, we'll really need to re-up via free agency, and trades using expiring contracts to have a legit chance at a three-peat (or second in three years)
Man, I really strafed away from Bill Walker, I'm sorry.