HTML5/CSS3 text editor for OS X? I am looking for a text editor that supports HTML5 and CSS3, allowing you to add/edit new properties, like rounded corners and so.

It doesn't have to be a visual editor but it has to have support for CSS3 and other new stuff like rounded corners.
There are two all-in-one solutions specialised for web development: Coda from Panic and Espresso from MacRabbit. Both have their pros and cons, just try them out and see which fits better for your needs. Hype is going through the news recently, but is more tool to create interactive and flashy HTML5 sites (as far as I understood it).