Webmaster Tools - RSS subscribers - Not all it could be.

The Webmaster Tools group has added subscriber counts to the set of tools. 

This will give you a count of how people are using Google Reader to subscribe to you sites RSS Feeds.  Would seem pretty cool, but not super inclusive.

Two big problems.

Only shows Google Reader subscriptions.
If you user FeedBurner, which Google owns, you feeds loose their association to your site. 

Oh well, nice try needs some work.  I would suggest to use FeedBurner and their stats are pretty inclusive. 

Maybe version 2 will be a little more accurate.