Phil89, it was actually the team option on his contract. I probably could have signed him for less on a longer contract, but I tend to play better with Tyler Zeller, so I thought I could let Anderson go and promote him to starter.
He's really just an extra body that (hopefully) won't bitch about his lack of playing time. I have Shaw, Gee, Kirilenko and Sefolosha that can fill the position, but with AK47 and Thabo playing other positions more regularly, I thought it couldn't hurt to get an extra. I probably need another centre as well at some point.
Blue1803, I'm not sure who Melo's joining in Phoenix. Minnesota looks pretty good with Love, Bosh and Rubio... at least on offense.
Lamrock (I didn't see your post initially), I decided I didn't need to make a big change to my core, so I just signed some role players I thought could contribute. Perimeter D was also a big problem for me last season, so I thought Kirilenko and Thabo would be good additions to help that. Of course, AMMO goes pretty much directly against that