I’ve just noticed the android market developer console has finally gained a "Comments" link where you can see the comments people have submitted on your app. Frankly, it was a surprise to me that they didn’t have that before (you had to look at the market like everyone else!), but at least its there now.
Now we just need loads of pretty analytic graphs, e.g. users by country, or distribution of installs by app version, and the uninstall reasons. Oh, and the ability to respond to comments (e.g. to ask commenters for more details about problems) would be good too!