I've released a new version of Flot. The API is now documented and legends have a background. And you can get the whole package as a zip/tarball. See the changes.
Lots of people are asking for pie charts. And some people have difficulty seeing the charts in IE 6. Which is really unfortunate because I can't reproduce it myself. All the machines with IE 6 I have access to render them fine. It's probably something silly, but it's going to take a bit of debugging to find it.
My plans for the near future mostly deal with getting proper support for time series and some of the other interactive stuff if I can squeeze it in. And get a forum or mailing list up running.
If you have a public application of Flot online, I'd like to hear about it, I intend to compile a list of real-world examples.