I have no compelling reason to move our family accounts from MobileMe to iCloud, though Find My Friends might be nice. Still, I'd probably do it -- except that I want to keep my iPhone and OS X Contacts in sync. Moving to iCloud for my iPhone means I need to move to iCloud on the desktop -- and i have only one Lion machine. Two others are Snow Leopard and a fourth won't run Lion at all.
I'd need to put Lion on the dual core MacBook, where it will run slowly even with encryption off. It should be fine on my i5 memory loaded desktop.
The bigger problem is that I'll need to upgrade software. FileMaker for sure, and probably a few other odd apps need Rosetta. The experience is guaranteed to be painful and expensive.
Apple's App Store is not encouraging. Lion gets 3.5 stars there, and the negative comments (only ones I bother with) are persuasive. That is, they complain about issues I know are real (such as software upgrades).
Meh. I'll wait until March or so. Maybe Lion and iCloud will both look better then.