A new update for Asus' middle-range Android tablet is rolling out at this very moment. Users on XDA are reporting getting the update notification, but it appears to be a little fickle with rooted devices. The abbreviated changelog claims this is a simple stability enhancement.
Update: This build is now available as a full ROM over at ASUS' TF300 Downloads.
To get the software on a rooted device, it is recommended that you take a few steps before applying the update.