I have heard from a person who is close to Colin Brown that he is going to have knee surgery soon which explains his placement on IR. Assuming my source is correct, which I believe is a family member, this would dispel the theory that Pioli placed Colin Brown on IR just to prevent him from getting taken on waivers. Colin Brown is actually injured however I do not know that the surgery is season ending but considering it is knee surgery it probably is season ending.
Putting Colin Brown on IR without an injury would not be a very smart move to just keep him from being taken via waivers on another team. On IR he is unable to practice, obviously, but also cannot attend team meetings yet still gets paid. The only thing he can really do is rehab and use the workout facilities. Plus his chance of being taken off of waivers would be pretty low considering he didn't show up very much in preseason and was a surprise draft pick as it was. However it would not be completely outside of Pioli's realm to put him on IR for a 6-8 week knee injury in which he would miss most of the season anyway.
This is my first post so some may not find this very credible but it is important information I thought worth sharing with everyone. I am an avid reader just not an avid commenter here on AP. AP is awesome and I enjoy reading it all the time so keep up the great work!