In the upcoming Jetty 7.6.3 and 8.1.3 (due in the next days), the Jetty-SPDY module has been enhanced with support for prioritized streams and for SPDY push (although the latter only available via the pure SPDY API), and we have fixed a few bugs that we spotted and were reported by early adopters.
Also, we are working on making really easy for Jetty users to enable SPDY, so that the configuration changes needed to enable SPDY in Jetty will be minimal.
After these releases we will be working on full support for SPDY/3 (currently Jetty-SPDY supports SPDY/2, with some feature of SPDY/3).
Browsers such as Chromium and Firefox are already updating their implementations to support also SPDY/3, so we will soon have support for the new version of the SPDY protocol also in the browsers.
Stay tuned !