Okay, I am on SL 10.6.8. I've migrated to iCloud and it works fine. I still have the MobileMe account showing in my Mail app in the dock.
Should I go ahead and delete that account? It's grayed out in Mail anyway:
Yep, I've been using iCloud on SL for about a week now. I just wasn't sure about deleting the MM account in Mail. Anyway, I went ahead and deleted it yesterday morning. All is still good.
Thanks!