A couple of days ago, Google announced that Android 2.2 would finally be rolling out to Nexus Ones over the air.  Since Google made the announcement, we assumed that that would be the final version of Froyo.  Today the company surprised us with another 2.2 build, this time numbered FRF91.  The gigantic update weighs in a 909 KB and will update anyone who is currently running FRF85B.  There's no word on what this update is for, but if you get the notification, go right on ahead and download.  If you don't want to wait, you can download FRF91 from Google here.  Lastly, Droid-Life warns that Motorola DROID users should stay far away from this update.

Judging by the size of this update, there must have been some small bugs that slipped by Google in the FRF85B build.  It's surprising that we haven't heard anything from Google about the update, but maybe they're too busy rolling out the update to share the info with us right now.  If the big G says anything about this upgrade, we'll be sure to let you know.  Until then, hit the download link above and tell us what you find!

Via Droid-Life