Moviestorm
…speaking of Machinima. I was hired to do a sample project for Moviestorm in Cambridge a couple of years ago when they we’re just starting out. I think they are progressing along nicely. You can download Moviestorm from their site. Modding is still a bit of a hassle and I don’t know how far they have developed imports of motion capture files (something I was really eager for them to do). I’ll keep watching them and I’m using Moviestorm as a previz tool on some of the things I’m working on. Another note is that they should clean up the interface design a bit.
I thing Machinima software should be developed to support 3rd party rendering engines – so that you can buy a powerful renderer and ad it to your workflow if you need it. I’m not a programmer so I don’t know how difficult that would be but a lot of 2D packages works that way.