Chrome or Safari are recommended for the above demos; Firefox is still lagging behind in speed, though that's likely to improve in the near future. Firefox also has a new, experimental, API for manipulating audio data in JavaScript. (Apparently people are going to be doing FFTs in JavaScript in the future, which presumably won't make your browsing experience any faster.) It requires custom developer builds of Firefox (i.e., it's only for the hardcore at the moment), but people are already starting to experiment with it. Potentially most impressive so far is a project to port the Pd graphic audio programming language to JavaScript and have it run entirely in a browser. Meanwhile, here are some more audio API dems, including ones combining the audio APIs with WebGL to present 3D landscapes which respond to the beat in music and and graphic equalizer, sampler and speech synthesiser written entirely in JavaScript. I wonder how long until someone writes an entirely HTML5-based Ableton Live-style sequencer.
Typography is also shaping up nicely under HTML5, with a standard embeddable font format agreed upon. Google have released a web font embedding API, and made available several free font libraries through their content distribution system. They look, well, like free fonts; for those wanting more (and willing to pay for it), other groups of type foundries are jumping on the bandwagon; fonts.com has fonts from major foundries like Linotype, Monotype and ITC (at last, you can set your site in authentic Helvetica for people who aren't Mac owners), and über-cool Berlin-based outfit FontShop have joined the game as well (bringing the clean European stylings of the likes of FF DIN and FF Meta to the web). One notable omission, though, are 1990s grunge-typography hellraisers Emigre, who haven't yet made the leap.
Finally, here is an article on some of the things one can do with CSS3, from transformations (i.e., rotating entire elements, including text and layout) to keyframe animation, all done without a single line of JavaScript.
Can't you run Safari under Wine?
You actually made me lol. You know, it never ever occurred to me. Given that I've already got FX, Ch, Opera, Konq, and Midori installed, the idea of using wine to install a browser seems...an extravagance? An Oddity? Heh. I also note that I'm not the first whining mongrel to feel this way: http://apple.slashdot.org/story/10/06/06/1344256/Apples-HTML5-and-Standards-Gallery-Not-Standard
Which, if I had actually followed through and rtfa before posting here, I would have discovered that it's a marketing ploy - if you go straight to the demo page in any html5 compliant browser, mostly it will work (apart from the non web standard stuff :) ) https://developer.apple.com/safaridemos/
The Apple showcase is funniest because it doesn't work on Linux. All of the other pages work in Chromium (from the ubuntu ppa) and Firefox (v3.6.3)...but Apple throws an error - "You’ll need to download Safari to view this demo." Demos of the future of the web, using the marketing technologies of the past!