Change from expired .mac apple ID to a new .me?

I set up my iPad using my apple ID which is my expired .mac address.

I'd like to set up a .me email for iCloud that I can actually use but keep my apple ID for iTunes purchases.

Everything I've read says to do this when you first set up the iPad....

Is this possible? Would a wipe of the iPad work or is that not necessary? My phone is on iOS 5 but my laptop is on 10.6. Will the cloud get screwed up if I do that?

Thanks in advance.