I'm currently running my HTC Desire on 2.1 (O2 branded from the UK, if it makes a difference) which has been rooted via Unrevoked. I've just now been prompted to upgrade it to what I assume is 2.2 via an OTA update. I'd quite like to do this but I'm assuming this will cause me to lose my root. Unrevoked seems to now say it supports 2.2 as well as 2.1 so would it just be a matter of doing the OTA update and re-rooting with Unrevoked?
Also, I've never performed an upgrade before, do I lose all my apps/data/configs? How long does it normally take?