Here is a trade that could work:
Michael Redd + 2009 1st round pick(top 7 protected)
Wally Szczerbiak, Danial Gibson, and 2008 first round pick
the Cavs would get a prolific scorer who can hit jump-shot or create his own shot to go along with James. With a lineup of West, Redd, James, Wallace, and Big Z the Cavs would be serious contenders for the next two years.
The Bucks would get a big expiring contract in Szczerbiak and would get two pieces for their rebuilding process in Gibson and the 19th pick (hopefuly Brandon Rush) Sessions, Szczerbiak, Randolph (8th pick), Yi, and Bogut along with a bench of Rush, Gibson, Mason, and Bell could sneak into the eighth spot in the East.
I also think the Bucks will trade Villanueva and Williams at some point during this off-season.