As soon as the upcoming Dropbox API is released and gains footing among developers, I am out of MobileMe.
As a freelancer the greatest value to me is the syncing of calendars. Now I know if I have another job on the day someone calls me up while I'm on location. No risk of double booking or sayin no because you thought you were working that day.
iDisk is great for sending big files that are password protected. I could probably do all these things for free, but now it's just to convenient and easy for the relatively small cost.
I do think it can be improved a lot though
Now if only Dropbox would offer a $4.99 /month, 15 - 25 GB account.
As for DropBox, I've been hearing so many good things I decided to check that out as well. Very nice service. Syncs well & integrates well. It does a good job of replicating iDisk. But to get more than 2GB free a month, which I would definitely need, it's $9.99/mo for 50GB so the cost is actually more than MobileMe at $119.99/year and 50GB is more space than I need. And that's all it is...space. And I can bump up to 40GB on MM for $150/year but I don't need that.
If you're working on multiple Macs, then you can enable iDisk syncing to Off and you'll always be working off a synced version.
Also don't like @me.com as the domain for the email address.
I use it to host my web pages as well, so it's not really a bad value. I track two iPhones with Find My Phone, and the push email is an added bonus.