Good to see Google, Mozilla, and Apple collaborating on fixing cross-browser CSS compatability issues:
You can track progress here.
Well, this is a grim collection from Dave:
There are some cases where even using plain ol’ HTML causes accessibility problems. I get frustrated and want to quit web development whenever I read about these types of issues. Because if browsers can’t get this right, what hope is there for the rest of us.
It’s worth clicking through each link he lists—the situation is often much more nuanced than simply “Don’t use X.”
Purely for my own benefit because I keep needing this URL, here are the current outstanding issues registered at the W3C for HTML5.