Backup restore is fine, but it really did not address the question. Because you are doing a clean install, you are reverting back to the basics.
You can slipstream the SP1 update into the install program and create a new disk. It's somewhat involved, but would put you that far ahead of the game. I suppose you could add other updates, but at that point, I would just as soon let it run overnight to update the 100 or so updates that come forth. One thing I have done is do the Service pack update before going to general updates, otherwise it will do a ton of updates then later add SP1, and update some more. Many of the initial updates are in SP1.
You could also slipstream other installers in the initial install disk as well.
That's the good thing about 2011 Essentials and WHS, it keeps old copies of your backups so you can go back 6 months and do a restore from 6 months ago and just do those updates. All your programs (that were there 6 months ago) would be intact. Still have to do a lot of updates though.
