The current version of Hightide is available to download is currently based on Jetty 6.0, but a revised version including Jetty 7.0 will be available in the near future.
Lastly, the makers of Jetty, Webtide (bought by Intalio last month) have also announced Jetty-Hightide, an open-source offering which includes a number of open-source stacks including.