Look for releases of Jetty 7,8 and the first RC for 9 within the next couple of weeks.
The largest change was a usability refactor of the websocket api between M4 and M5 stemming from feedback from the CometD project.
Otherwise the changes in this release are:
jetty-9.0.0.M5 - 19 January 2013
+ 367638 throw exception for excess form keys
+ 381521 Only set Vary header when content could be compressed
+ 391623 Making --stop with STOP.WAIT perform graceful shutdown
+ 393158 java.lang.IllegalStateException when sending an empty InputStream
+ 393220 remove dead code from ServletHandler and log ServletExceptions in
warn instead of debug
+ 393733 WebSocketClient interface should support multiple connections
+ 395885 ResourceCache should honor useFileMappedBuffer if set
+ 396253 FilterRegistration wrong order
+ 396459 Log specific message for empty request body for multipart mime
requests
+ 396500 HttpClient Exchange takes forever to complete when less content sent
than Content-Length
+ 396886 MultiPartFilter strips bad escaping on filename="..."
+ 397110 Accept %uXXXX encodings in URIs
+ 397111 Tolerate empty or excessive whitespace preceeding MultiParts
+ 397112 Requests with byte-range throws NPE if requested file has no mimetype
(eg no file extension)
+ 397114 run-forked with waitForChild=false can lock up
+ 397130 maxFormContentSize set in jetty.xml is ignored
+ 397190 improve ValidUrlRule to iterate on codepoints
+ 397321 Wrong condition in default start.config for annotations
+ 397535 Support pluggable alias checking to support symbolic links
+ 397769 TimerScheduler does not relinquish cancelled tasks.
+ 398105 Clean up WebSocketPolicy
+ 398285 ProxyServlet mixes cookies from different clients.
+ 398337 UTF-16 percent encoding in UTF-16 form content
+ 398582 Move lib/jta jar into lib/jndi
+ JETTY-1533 handle URL with no path
cheers!
jesse