Mint 11/ Mint 12

[#1]

When Mint 12 becomes available will it be a simple matter of upgrading from Mint 11 to Mint 12.?
I am well impressed with Mint 11 and don't want to bodge it up attempting to upgrade and messing up the whole system.

[#2]

The recommended way of upgrading is to backup what you need and do a fresh install over your old install. You can keep a /home if you have it on a separate partition (recommended), then using the Mint Backup tool backup your installed software list and after you have installed the new version you run it to install the s/w again.
I tend to also backup my entire /etc folder as I have a lot of tweaked files in there, fstab/exports/configs etc. If you have a "normal" install with one drive and no network shares the standard backup routine will work fine.
If your /home isn't on a separate partition then I would recommend moving it to one first it makes upgrading MUCH easier.