I've always defended MobileMe as being worth the money, because I liked having everything in one spot, and more storage than a (free) Dropbox account. I've never had any major issues, but this has totally screwed me up tonight. When it's "fixed," I wonder if I'll have to sign out and sign back in. I tried that once, and all that did was screw up my local iDisk and then make it spend 3+ hours re-downloading everything.
I signed up for a Dropbox account now so that I have yet another backup of everything. If this issue persists, I may consider switching away from iDisk...
(Though I suppose I should be happy that I'm not actually losing data, just makes everything take longer when it isn't working properly).