Almost anything dynamic on the client-side - that's alot
I remember trying to code a NS4/6, IE5 drop down menu. It was so irritating.
There's no way to develop a menu that works the same on all those browsers without using client-side scripting.
I've seen this happen before. Every time something new comes along the purists jump on the 'this is the only solution' band-wagon. Why limit yourself? Why work with one hand tied behind your back? Fill your toolbox to the brim and learn how and when to use each tool.
When the DOM started becoming standardized, many js dom enthusiasts started jumping on the dom-only band wagon. They hurt their cause more than they helped it. The current css enthusiasts should learn from that.
And so, to you CSS gurus who have discovered wonderful things (which I now use) - Thanks!
And the same goes to the JS gurus - I use your discoveries too.