Forum Moderators: open
If you're the static design type, yes, 600 is beginning to fade off, 800 is safe, many are going even wider.
Over the last 8 months on consumer type sites, the numbers are roughly showing as:
100% design coverage @ 800 pixels wide
80% design coverage @ 1024 pixels wide
Design coverage is the number users who can see the page without scrolling sideways.
I normally publish this in a RSS feed, but haven't updated it lately.