Still trying
Luckily I have a test box I use. First tried the UPGRADE option from update manager and it killed the systems stone dead, no 10.10 no 11.04.
Downloaded the .iso and installed clean, it sort of works, but with my nVidia card no Unity and for some reason no networking, though it says it is working it is either very very slow or non existant. Picked up an IP when booted but then refuses to ping or be pinged across my network.
Once I get networking going properly will look for nVidia drivers (I assume Ubuntu clean install has reverted me to the open source ones), then force Unity to run (the machine should have enough grunt despite what the install says)
Then I'll stick with this on TEST until Canonical sort the problems out.