Hey, if you get a chance could you try out my dissertation project? It's a multi-player space shooter with some RPG elements, done in C#/XNA:
Galactic Arms Race (GAR)
Let me know if there are any serious installer or game issues, or if any of the instructions are unclear. Logging onto the "GAR Official 1" server and shooting people will help me collect dissertation experiment data.
Posted a couple threads on this during development. Zarcath did some of the NPC dialogue. Here's some pics of how it finally turned out.