The feature that you've suggested is one that I've actually looked
into and am interested in implementing. Unfortunately, Google doesn't
provide any sort of API for directly accessing that information. To
access that sort of information, the plugin would have to scrape data
off of the FB site. However, scraping is very finicky and can break
if FeedBurner ever changed their user interface. In addition to this,
Google placed restrictions on scraping in section 5.3 of their account
terms of service that legally preclude me from doing this.
For that reason, even though I'd love to do this, I'm not able to
implement that feature at this time.
Sorry for taking so long to get back to you about this,
Jonathan