Absolutely and I agree that the ease of use is worth it for many people but much of what you described can be done for free. While it may take some more effort, the features of MobileMe can be found elsewhere.There's a lot more than that.
Since I have a Mac (iBook) that I use when I am on the road, the ability to keep my bookmarks, E-Mail accounts, Keychains, iCal info and address book synced with my Mac at home (and my iPhone) is really nice. If I change anything on any of my devices it is all sync'd to the others automatically. The MM e-mail pushes to the iPhone as well (vice pull for the others, including G-Mail) and is really handy for quick e-mail real time when out and about.
Absolutely and I agree that the ease of use is worth it for many people but much of what you described can be done for free. While it may take some more effort, the features of MobileMe can be found elsewhere.