Even as a Windows guy I can agree with the OP, stick to the "Every Other OS release" rule*. Like it or hate it, Windows 7 is a beutiful piece of work. Now with that success\fallback OS Microsoft will use Windows 8 to test out "New Features" that intend to make it easier for Grandma to send E mail but actually end up causing us great deals of pain.
I like the way Smartphone OSes work (I got my Samsung Galaxy S+ with Android today and I love it). When I've finished my current project I'm thinking of playing with XLib to see if I can write something that works the way a GUI on a Smartphone works.
I'll be honest, IMO Unity isn't bad. True, it was designed primarily for netbooks (features to conserve vertical screen space, new scrollers), however I found it just fine on my 15.something" laptop computer as well. I haven't had any major usability problems with it, despite its Lenses feature being somewhat broken (if you install a lens then all the users get it and one can't easily add/remove/change them per-user, not to mention that the key command to activate a lens is not configurable AFAIK).
I'll be honest, though, I would prefer GNOME 3 on my laptop. October, Albatross, it'll be officially supported in October... (I'm not interested in using the PPA.)
Gnome 3 support is coming to Ubuntu (and it's derivatives by extension)? this makes me a happy alex.
Anyways, I completely understand the philosophy behind what they are doing with the user interface. What they (Microsoft, Google, Apple) are shifting to a merge of their mobile and desktop top OS's, though at the moment for google it's just tablet and smartphone version of Android with no hints at chrome os dropping in. Windows 8 is supposed to support arm. Lion has really good touch screen support and a lot of parallels to iOS' functionality, or so I've heard. I think the idea is to make it work the same way on as many platforms as possible, and I'm willing to bet the next step or so will lead to future windows being cloud based as well as future Mac, so you can use any software you own on any of your devices from anywhere while accessing any of your files.
I honestly find the W7 start menu to be much more efficient than previous iterations. Most of the time, the program I'm looking for is in the list of recent ones, and when it's not, it's still quicker to type in part of the name in the search box than it was to manually navigate to it, whether with the keyboard or the mouse.
What did bother me was the new context menu for taskbar buttons, but there's a handy program that not only corrects that behavior, but can also, for example, set the middle mouse button to close a window.
Now, that is efficient.
I personally like Unity, especially the fact that it runs smoothly on my 6 year old PC.
As to windows 8 - well, it doesn't strike me as very appealing or comfortable to use, but I will see how it actually performs when vendors start forcing people to buy it along with their PC's like, 5 minutes after the release of Win8. Guess I'll actually have to stop being lazy and go to a real computer shop next time I buy one
I don't think it's "god awful", it's not even in Beta yet and will probably change a lot before it releases. I say it's about time OS vendors do away with the traditional desktop metaphor: it's ancient, and in this day and age it's becoming less and less relevant. I'm not exactly excited for Metro, but I'll wait and see.
What I *am* excited for is the rewritten process scheduler, Hyper-V, faster boot times and the new file management improvements.