@me vs Apple ID
I'm a bit confused. My apple id is my normal email address, When I go to me.com I sign in with my normal email address and not a @me.com account. So do I need to make an @me.com account to have all the new features or will I be ok with my normal email address which is my apple id account?
My experience is that, despite being prompted to create a brand new @me.com email address by the iOS5 beta, it has been linked to my Apple ID.
When logging in to the App store, for example, I can log in with my newly created @me.com email address, and it will log me in to my original Apple ID account. However, the opposite is not true. I can't log in to the iCloud "mail" section on iOS5 with my Apple ID credentials an recieve emails sent to my @me.com email account, despite it being linked with my Apple ID. Nor can I change the login information, once entered, without wiping my iPad.
I would guess that you will be able to associate (link) @me.com email accounts with an Apple ID and it is the @me.com emails that sync with the iCloud, not the Apple ID. It's even plausible that you can associate multiple @me.com emails with a single Apple ID. That would enable you to use your apps across multiple devices (tied to your Apple ID) and sync different combinations of devices to the iCloud that have different @me.com logins but the same Apple ID for sharing apps.
Apple has stopped accepting new @me.com email accounts (except it would seem via iOS5 betas). I would guess they will open the doors to new (free) @me.com email accounts with the official release of iOS5, and these credentials will be used to sync data to iCloud, keeping App Store purchases seperate by having them associated to your Apple ID.
@me.com = iCloud data sync credentials
Apple ID = App Store purchases
At least that's how I understand it.