I'm not a tremendous fan of Lessing and only really read one book of hers called "Briefing for a Descent into Hell" which I found quite fascinating. She has created a body of interesting work and I'm not unhappy with the choice but still would like to see Margaret Atwood win it one of these days. I think she deserves it as well for her body of work and her contribution to putting Canadian literature on the map.
The following links to a rather interesting interview with Lessing about writers, writing, and how we should read novels.
BBC - BBC Four - Audio Interviews - Doris Lessing