Stoic Joker: well, I guess it's not that strange that it's possible to find an exploit that works across multiple versions; I was thinking that this implied the same exploit code could be used, which would be quite something... but that isn't mentioned anywhere; brainfart on my part.
Anyway, I've read a few blogs here and there about the exploit, and the details are indeed a bit scarce. But from what I understand it's a javascript bug that's being exploited - and while much of the info is badly worded, I believe that you only need to visit a "compromised site", not actually clicking on anything on the site, which makes it pretty dangerous. Especially now the exploit code is in the open, and will be used for drive-by exploits. Yes, us power users have noscript and adblock, but a lot of regular users don't.
Also, various blog entries mention that IE8 sandboxed mode helps
mitigate the attack, and DEP (default in IE8, optional and default-disabled in IE7) also help mitigate the problem, but it's not mentioned
how much it helps - like, whether sandboxing lets the exploit do it's stuff, but limits which files can be read/written... and whether DEP might let the browser crash, but not run the exploit code. All we get is "mitigates"