Hi Lukeb,
Before you download the 3.0 OS you should read as much as you can about it before you go ahead and install it. On the chance you found it and downloaded but have not installed it yet. [If you do decide to wait a little longer like i wish i did.] if you want to restore your phone with the 2.2 just use shift button on your keyboard before you click restore. once you download the update it will try to install itself everytime you click restore using the shift key is the only way to take control over the operation.
Dont get what im saying wrong. there are many things about the new 3.0 OS I like but there are also things i dont like. and since this is just my 1 opinon it really means nothing on the grand scoop of things. thats why i say you should read what others are saying about.