The Mac App Store will most likely be accepted and used by most Mac users without much problems. Most people apparently don't care about ugly and inconsistent user interfaces, and the added benefit of central control over your applications will most likely make those that do accept it as a necessary evil. However, there will inevitably be people like me who don't want to have anything to do with the Mac App Store, and just want the damn thing to go away.
Since I was looking into cleaning up my Mac anyway (I needed iTunes to go away, since I don't use it and hate it with a passion), I decided to see what would happen if I were to remove the Mac App Store as well. It's quite easy to remove both iTunes and the Mac App Store; while Apple lists a 29-step (!) instruction set for removing iTunes, I just used AppCleaner, which seems to have worked just fine. I will still fine comb the file system with the 29-step guide by my side to make sure everything got deleted, though. Yes, Mac OS X looks good from a distance - but try and do something not approved by Cupertino and you're in a world of hurt.
I decided to delete the Mac App Store in the same way, and it seems as if it has worked. You can just drag the Mac App Store binary onto the AppCleaner window, and it'll find the associated files of the application outside of its bundle, and delete them as well.
It seems as if Apple has somewhat thought of this scenario (maybe they had enterprise users in mind?), since upon reboot, the menu entry in the Apple menu has changed back to its pre-10.6.6 state, where it pointed to Apple's Mac OS X software download page. However, as you can see in the shot below, upon trying to open an unsupported file type, the dialog still shows the newly added "Search App Store"-button. Clicking this button does nothing.
Overall, I haven't yet encountered any issues, but of course, this being unsupported means you could still potentially run into problems. I am personally not happy with the Mac App Store being snuck onto my machine without any way of telling Software Update not to, or without an officially supported option to remove the darn thing.