I'm a relatively recent convert to Ubuntu after many years of being a Mac OS X user and I'm really quite impressed by how well it functions. The reason I switched from OS X is due to the fact that Apple seem determined to turn their desktop OS into an extension of iOS with all kinds of integration with social media and other items of "added functionality" that I really don't want.
I'm a great believer in having things segregated unless I deliberately choose to connect them. I do use Ubuntu One (very useful) and Picasa (very handy) and even Facebook (begrudgingly) but I don't want these things to be plugged into the depths of my OS by default and I'm very particular about what I share.
Ironically, this seems to be the direction that Ubuntu is heading as well, so it made me wonder if this was just something that I didn't like or if other people found it annoying as well?
(Before I get flamed to a crisp I would like to point out that I accept the fact that I could just a grumpy old man before my time and that I was raised in the computing world by a tribe of bearded Unix admins who promised me that the whole Linux thing would blow over and wasn't worth worrying about!)