I would NOT do it. If I were to trade for the #4 pick and want to keep it, I'd draft young PG (Knight or Walker) and keep Batum and grow with them. So, I'd prefer in that case to trade Wallace. For me the team is at a crossroads; either go for it now; trade young and future pieces to win now OR.... trade older guys and acquire younger guys and grow them up.
Check out the clutch stats thread from a few weeks ago; he's actually pretty good when you take a holistic look at all clutch stats. Granted, he's not a world beater yet, but he's also steadily improved a lot of key stats every year, dealing with a position that sees him change responsibilities quite a bit each game.
Lets get young guys so they can grow together... UGH! Do the Lakers ever say this? Yes lets get young players and let them grow up for 5 years then watch them leave or get hurt. I guess paul allen plans on living to be 98