Can see both sides of the arguments on this one, SL is by no means the earth shattering release some people were making out, feels like leopard, there's a few nice tweaks here and there, might be a bit more responsive but don't know if that's just because I think it should be.
However I think the point is being missed, Apple themselves have said this release paves the way for the future, it's a foundation builder. You wouldn't go look at laid down foundations and go "I wouldn't want to live there, my old house is better." Once developers start programming properly for GDC, Open Cl and 64 bit apps, then the improvements will start becoming obvious.
I'm not a fanboy, run Windows, OS X and 2 Linux distros at home (am a geek though lol), and fairly new to Apple so haven't seen the development of Apple products the way the OP has and the disappointment attached. Got to say for general day to day use I prefer OS X, love the stability and ease of use.
Just gone from a HTC Touch Diamond running Windows Mobile 6.1 (also tried a 6.5 ROM), to an iPhone 3GS a few weeks ago and got to say it is a massive step up.
Guess what I'm trying to say is Apple might not be as progressive as the OP thinks anymore, but they're still miles ahead of the competition and try to have more of a long term perspective on SL.
*Note amazing how people have a knee jerk reaction to some one posting their opinions*