This is a bit off-topic, but only because some of the comments made here are making me wonder about Unity3D. A while ago, I kept hearing a lot about Unity3D while talking with teams around the DC-NY area. So I looked into it, and made a small game mayself, just research - non-commercial, to see if it was as useful as everyone claimed. Everything they said was true, I was able to get a simple game done in a weekend. B…
It is not that convenient to work with larger teams on the same project and documentation on how to do that is sparse.
It has been done however, even EA has adopted the engine for a few projects (Tiger Woods Online) and there are whole MMOs built with it.
As more and more larger companys start to use it, the focus of the developers behind Unity will shift to all those Team issues.
The pricing and license agreement is VERY competitive and they are having sales every few month.
Qualcomm even released their Augmented Reality Platform as a Unity Package which I currently use to do some projects with.
Overall i think its the best middleware package for indies and mid-size companys today.