MobileMe Mail & Bookmarks After June 29th

I'm not going to be able to buy a new Mac that meets the iCloud system requirements until sometime after July 1st! I've chosen to keep to keep using my mail after MobileMe ends, even on devices that don’t meet the iCloud system requirements, including this old Mac I'm using to write this message. But I'm worried about easily being able to migrate everything, including my keychains, bookmarks and mail accounts to my new Intel-based Mac once I purchase it. Any suggestions?