It's still too early to decide on the trade. The trade all comes down to Shaq's health. If he is okay, the team is okay. It's even okay to have Nenad as our 2nd string center... He just can't be our starter going into the playoffs. However, I don't think Shaq will miss the playoffs. He'll play, hurt or not, in order to get that 5th ring.
I've had an inflamed achilles before... similar to Shaq's injury. I was out for 2 months. It's bad but nothing that you can't push through with a little adrenaline from the crowd.