CSS3 is awesome. While IE is a bit behind again, the new IE9 will be out sooner then you think. Start using CSS3 now and when IE9 arrives then you will be ready. The key is to make sure the site degrades gracefully.
The websites I’ve been working on lately are corporate sites. These types of clients have very different needs then a blog or a networking site. They do not need IE9, or 8 for that matter. Corporations don’t want there employees surfing the web while at work. So it’s almost a benefit for certain sites to look ugly or be unusable. Youtube doesn’t support IE6 at all anymore. You think the office cares.
So here’s the thing, these sites just have to work. They don’t have to blink or be interactive at all. What’s most important is the message. Can people navigate the site? Is it intuitive? Can they get the info they need, or rather the info you want them to get? As long as users can do this then it might as well be black and white straight text.
Of course clients want it to look cool, but the advanced CSS3 stuff… Well if they want that then they can go upgrade their browsers.
This is where you hear about degrading gracefully. This is different then browser compatibility, where the site looks and acts the same on all browsers. What degrading gracefully means is that it doesn’t look bad on a lower browser like IE7 or 6, or even on a text only browser.
If not then maybe you should think about restructuring your html.