Software version 5.07 has appeared on my 360 boxes. As per usual there is no obvious change - at least on an initial inspection - and no indication of what elements have been upgraded.
There is nothing there yet, just the usual 'we've squashed a few bugs' guff. I tend to get updates early on in the cycle, so there may be something more informative later. I did notice that version 5.06 has been skipped.
One new 'feature' I have noticed since the update is that the box now starts up on the Home screen with the last channel viewed in a mini box rather than the last channel viewed full screen. I'm not altogether sure that this arrangement is an advance on the previous version. There is still no new info about what the update contains. I'm guessing that either it's mostly under the hood or something I have yet to find.