No, it's entirely different actually. A lot of applications hook into MobileMe to allow syncing, and don't offer any alternatives.
Address Book, for example, plugs right in. Sure, it's got Yahoo and Google syncing... but they break routinely, and I had to fight with it to not delete everything on both ends when I first hooked them up. I'm now using Soocial to sync them because it was so buggy, and none of the options pass images back and forth. Unless I'm forgetting something, MobileMe does, and it preserves all data correctly, unlike any option I've found.
I believe iWeb also hooks in, letting you make changes to your site and push them out quickly. As do iPhoto, iMovie, etc etc. And when was the last time you could find your iPhone and / or wipe it if it was stolen with a 3rd party tool?
Prior to Dropbox, what easy option was there aside from MobileMe? And remember that all this happens behind the scenes, so you can't throw up dialog boxes ever, and still handle everything.
There's nothing comparable because there essentially can't be unless they allowed you to change what MobileMe server you connect to. And show me something that handles everything MobileMe does, in one site with minimal / built-in setup on a Mac, and I'll accept that Gmail in Mail.app is the same thing (when you can't specify which folders you subscribe to).
---
I'm not claiming MobileMe is worth the money (it's not, IMO). Nor that you can't simulate it with an amalgam of other systems which don't necessarily play nicely together. But how many average-users do you think do that, vs how many would use a 3rd party option if all they had to do was change one text field (ie, mobileme.apple.com => mobileme.anothersite.com)? It's entirely within Apple's ability to present that field.
Tell me I'm lost in the sarchasm.