Biggest impact of this trade would be on what it would do to the Spurs' offensive philosophy. Bonner, Finley, and Bowen between them took over 8 3-point shots/game last year (40% of the team total). Manu will probably pick up some of that (although looking at his numbers you could argue that he shouldn't), and RJ is probably going to get 2-3 shots a game. Can't imagine Mason taking more three-pointers than last year in fewer minutes.
So is Pop ready to abandon the Spurs' reliance on the 3-point game, and put more emphasis on low post, slashing, and getting to the line? That (in addition to the defense) would be a nice return to old-time Spurs Basketball.