It's interesting to see the interplay between a completely new user to Linux and more experienced users; especially in regard to Unity. It's easy to believe that it's a curmudgeon issue but I really think it's a matter of once being able to customize things and no longer being able to. So a new user, used to Windows and/or Mac, where what you get is pretty much what you use, Unity is familiar and easy. To old-time users it's a PITA. But new users is where Ubuntu wants to go and, from SevenCubed reaction to it I am greatly heartened.
I have, by the way, found that to become used to Linux you must abandon Windows; at least for some period of time. I have watched many, many users load up Linux on an old machine and play for a few hours but go back to Windows for "real" computing. Maybe Ubuntu and Unity have discovered a way around this. But so many users become accustomed to only the applications they've had on Windows. Even with Firefox and Chrome being virtually identical on all platforms this is common.
For the record, my first OS was RT11 on a DEC in the 1970s. From there I went to Xenix, then to DOS, then to Windows, then to Windows with DESQview, then to Linux (in 1994). I have run many variants of *nix (including Coherent, FreeBSD, SunOS, etc.) and find myself much more comfortable with Linux as the "Swiss Army Knife of Operating Systems".
I have Linux boxes (mostly running Centos) scattered around the relatively small (in population) county where I live where they quietly perform tasks mostly unseen by the clients. I have run Ubuntu 10.04 on a desktop for a few years but have to change since it no longer will update. Probably to Mint.
But I have NEVER dual-booted. :)