It is a way to export in XML the comments leaved by the users on the Android Market?
On Facebook the Graph API enables to pull comments:
"Comments can now be searched and exported so developers and website owners can highlight the most interesting comments, perform analysis on the comment stream, reward top commenters, search through existing comments, and use comments to improve SEO on their site. For example, a news site could highlight the most popular comments or display an info-graphic comparing the number of “pro” vs. “con” discussions created on a political topic." Source : http://developers.facebook.com/blog/post/490
On Facebook, comments for every URL can be accessed via the Graph API:
https://graph.facebook.com/comments/?ids={YOUR_URL}
FYI. Same question posted on the android-market website: http://www.google.com/support/forum/p/Android+Market/thread?tid=68aba0273ccb35ca&hl=en