Transitioning from MobileMe to iCloud with Apple ID & Different moblieme.com E-mail Addresses

I am currently on 10.6.8, but looking to migrate to 10.7.2 in a couple of weeks. I also have two e-mail addresses that I use which are as follows;

1. id@domain.co.uk (this is my Apple ID and is my primary e-mail address which I use with Entourage and will use with Outlook going forward
2. id@mobileme.com (this is used only with MobileMe and Mail in 10.6.8 also uses this

As you can guess the Apple ID is also the one that I use within iTunes for all of my store purchases. This e-mail is also my primary e-mail address and I pick up this mail using Microsoft Entourage 2008 (will be Outlook 2011). I use the MobileMe e-mail address as secondary e-mail, but this is linked to my 2nd generation iPod Touch (I realise that following the transition to iCloud this won't work anymore).

Within 10.6.8, I have configured the MobileMe account within System Preferences.

I am planning to migrate to iCloud following the migration to 10.7.2. I was wondering if someone would be able to clarify what will happen in terms of the user experience when I do this and link my Apple ID to OS X 10.7.2 as per the 'Using the Same Apple ID for Store Purchases and iCloud' configuration within the following article;

http://support.apple.com/kb/HT4895

Obviously, all of the calendars within iCal are items that I wish to migrate from the MobileMe account to iCloud. I don't mind about the mail items that are contained within the MobileMe account, as its a secondary e-mail that I use for my own purposes. However it would be handy to keep thie MobileMe e-mail and move this to iCloud.

I'm planning to get an iPhone 4S in the new year and a new iPod Touch (as the current one is 3 years old and the battery isn't as good as it was).

If you can clarify what happens, that would be excellent.

Thanks,