There's nothing wrong with MobileMe or .Mac (they both have bad names -- thats the biggest issue)

They weren't huge sweeping successes because they didn't have enough features and cost a LOT. But the features they did have worked well.

MobileMe was just .Mac rebranded with more features.

iCloud is just MobileMe rebranded with more features.

Apple is smart for recognizing when they need to rebrand for communication facilitation. But don't be fooled. iCloud is just MobileMe with a facelift a few new features.