If your scared about some iOS UI changes added to OSX, I'm surprised your not running from Windows 8 which is attempting to be a universal OS with Windows 7 phone interfaces added into it. I have windows 7, but am not crazy about the idea of the phone's UI being added to it....we'll see the closer they get to release date.
I'm somewhat concerned about that, too. Win7 is actually the first version of Windows I genuinely like for general purpose use. I liked NT4 and Win2k enough for what I used them for at work, but for personal use at home, I was never really happy with anything until 7. That's a bit of an understatement. More like somewhere between despised and grudgingly tolerated, depending on which version and what I was doing. Heh. Anyway, aside from the continuing lack of a satisfying Unix layer and the occasional things that have persisted so long without being updated that they've become anachronisms, Win7's finally pretty ok, so I'm a little worried about them screwing with that.
However, there is a major difference. Apple is very "You will do it our way or no way at all!" about things. They will probably change even more stuff in 10.8, and the stuff that's optional in 10.7 and can still be reverted will probably no longer be an option at that point. The advantage of that approach is that you can maintain a relatively consistent platform and institute changes fairly quickly, even on a rather large scale, whether it's hardware or software. They seem to take two years for things to be introduced/optional, two for them to be mandatory, and then after that whatever they replaced isn't supported anymore. You can still use it, but you're on your own. Great if you like shiny new things, specifically
their new things in the form
they present them, but it can get frustrating if your needs and theirs go in different directions, especially if you're a power user of any kind, and
especially if you're a developer. It worked well for me for several years, though.
MS, on the other hand, tends to bend over backward for developers and for backward compatibility, so I have a feeling that there's a much better chance of whatever crap they throw in being avoidable or disablable. You can still disable Aero and all the associated features and switch back to the rather painful Windows Classic theme in Win7, if you really want, after all, along with most of the services and whatnot it normally runs. Even if not, Win7 will be supported for
much longer than 10.6 will be; I'm pretty sure the new MBA won't even run anything older than 10.7, and I doubt anything else that comes out from now on will, either. They do keep sort of making attempts at winning people over over the years with various features and heading in different directions, but I think they still realize that one of their biggest strengths is the massive army of developers for their platform, so hopefully they'll keep that in mind and keep something usable underneath whatever crap they're putting on top.
If all else fails, I can always go back to Linux or something. Heh.