Few hours ago, MS pushed out a new dash update for the 360.
The dash + kernel, now at revision 16547 is a minor one (so it seems)
As usual, C4eva is going to investigate it and and will probably post a full log.
My prediction:
Nothing has changed other then a few bugfixes.
Never the less, if you value your XBL connection on your Xkey/flashed machine.
Withhold from updating for a while.
Various users are reporting that backups continue to work, both flashed drive users and Xkey users.
For the people with JTAGS/RGH/R-JTAG machines, expect an update to JRunner/XeBuild etc soon.
Source: pic of me mate + various forums on the backups section.