Looks like the ESE53 leak that's been floating around for a while now is the official OTA update that Droid users should be receiving starting March 18th. Verizon will be following the same strategy as before, releasing the update to a set number of people per day, though this time it is much higher ~250,000 a day. That means the latest anyone should get it is the 22nd (there are a little over 1m Droids in use)
Here's the post over at Engadget, with a link to the actual Verizon page detailing the update.
http://www.engadget.com/2010/03/16/verizon-posts-android-2-1-upgrade-details-for-droid/The features include:
-Live Wallpapers
-Multitouch Goodness (Browser, Gallery, Maps)
-2.1 Optimizations
-More
But exclude:
-3D app drawer
-5 Screens