I would also argue that MC should look totally different than anything Windows. I have very little respect for any kind of interface MS designs, and yeah, I'm an exclusive Windows user.
When we said "bling" they said no (so that you had to hack uxtheme.dll back in the days and what not, just to install something cool); when we said "speed", they said "bling" (Vista, 7 and whatnot). Great timing. Their interfaces are made for folks that don't know any better where the heck their files resides, have to be slapped over the face with big icons, front and center - "Click here, here it is, we know better than you".
i feel that there are really only 2 skins that are any good.
You made a fine point but up till that. Do you hear the uproar of everybody that ever designed a skin for MC (which is not exactly an easy job)? For the sake of illustrating the variety of tastes I'd say I use No.4 for standard view and it'll be rather difficult to convince me to use anything else.
Now, getting back to our favorite thing (that's MC, not Windows!), I would also plead for getting some improvements on the skinning side, although I'm eying more the Theater View than the Standard one. Not much, just say 3 months of pro-skinning oriented updates...!
Seriously, my opinion is there's a lot to gain on the interface side, (even) without tapping into Vista / 7 / Aero features.