I think this is a good deal for both sides. The Bucks were not thrilled about Jennings being the PG of their future. They pretty much were content with Jennings walk if he got a good enough offer. They got a guy with good potential in Knight, when they almost got nothing.
Meanwhile Detroit is clearly swinging for the fences with the potential on their roster. Smith, Drummond, Monroe (their most well known commodity), and now Jennings ( a guy who has potential if he can get his head on straight).
Plus detroit kept villanueva (sp?) and stuckey who are both expiring contracts, they can make good use of.
Edit: this doesn't really help the Bobcats, however, as we likely will receive their pick when they are a 6-9th placed team in the East
a future core of Jennings, KCP, and Drummond has got potential