Well, i'll start by saying this. I stand corrected. My previous assumption is now very wrong. That being said, bloglines is still our preferred reader.
From the Feedburner (who recently made google reader stats available) blog:
1. My Yahoo 54%
2. Google 21% (Reader + Personalized Homepage)
3. Bloglines 11%
4. Netvibes 9%
5. Live.com 3%