IMEISV is now at version 7. No other changes I can see.
I previously rooted and flashed Siyah 4.3.3 which resolved my issue with the sleep of death. This seems to prevent this new update from installing as when the phone reboots it shows the Siyah boot image and then boots back into the OS, when I unlock the phone it tells me that the update failed to install. I'm not in a hurry to install an update that resolves something I've fixed through other means, but I thought I'd share for those interested.