Suez, you don't have to use iCloud at all. It's totally voluntary. Until you are ready, just don't change from your Mobile Me account. You have until June 30, 2012 to make the change, but once you change to iCloud, you can't go back. Mobile Me becomes inactive as of that date. Don't feel like the Lone Ranger, there's lots of us who haven't figured out if/when we will make the move away from MM and into iCloud.
Since you don't have separate Mobile Me accounts, one of you lose access but only if you upgrade to iCloud. You can upgrade to Lion and not upgrade to iCloud, if you choose. That way you can keep using the syncing services for Mobile Me for both of you until your husband decides that he wants to upgrade to Lion too.
FWIW, if I understand everything correctly, when you do move to iCloud you will have to have 2 separate e-mail accounts for your 2 .me accounts(1 old and 1 new). You can share the same Apple ID for iTunes, but not for iCloud. Here is some more information about the changeover
Apple Posts iCloud Transition Q&A, Confirms iCloud Will Have Web Apps
I think the trickiest part is going to be, getting all your information over to the second person to move to iCloud. The first person is dead easy as there is automated transfer all your Mobile Me info over to iCloud. The second person will not have that same easy path because once you move the account, your old Mobile Me account is shut down so the second person loses access to the information.
I'm sure there's probably a good way to transfer the second person's info too, I just don't know how. I'm sure there are smarter people than me who can give you that information.
