Still no Windows Mobile 6 update for my Orange SPV M3100, but they did release an update to WM5 recently.
Installing said update turned out to be slightly trickier than I expected. I don't know if anybody else has experienced the same problem, but a word to the wise - don't try the update on Windows Vista!
The first part works OK - it connects to the device and interrogates it, but when it actually tries to connect and download the new firmware it fails.
Luckily, I still have a PC at home running XP (Media Centre Edition, as it happens), so I installed Active Sync 4.5 and rant he update successfully on that.
I'm surprised though - Vista's nearly six months old now and there must be others with the same phone who don't have the recourse to an old PC (!) to run the update.