Wow. Phoenix is really clueless. After trading away Ariza, they were trying to get a point guard, they got one (albeit not that good of one) and then they waive him. The chances of Ourbe re-signing with them is also pretty low this summer and they didn't even want Ourbe in the first place. So, they basically got nothing in that Ariza trade.
Rivers will probably want to go back to a safe haven with his dad on the Clippers, that way he will get some minutes.