http://sports.espn.go.com/nba/news/story?id=2559286
Porter was a good but not outstanding player who had a long and productive career. He actually knows Flip Saunders from a few seasons in Minnesota, though I don't really know how this will affect how he'll help the coaching situation.
He coached a surprising Bucks team that lost the majority of their talent (Allen, Payton, Cassell) in the offseason to a playoff spot (where they got rocked by the Pistons, naturally). That team was effective because of its offense, but they weren't so hot the next year (also coached by Porter) because of injuries to Ford, Kukoc's decreased effectiveness, and the loss of Mike James and Van Horn midseason. Both of these teams were pretty terrible at defense, but one thing I did like about Porter's first year with the Bucks was his offensive coaching prowess and his general ability to get production out of bit players. In the playoffs, our offense was looking stagnant (for a number of reasons), so maybe Porter's influence might be able to fix that.
I know no one really cares about assistant coaches, but he's a fairly big name and I figured he's worth mentioning.