As is the case for Linux, the Xen hypervisor developer community does not maintain a committed roadmap as proprietary software vendors do. However, the community strives to accurately track development for new Xen releases, with a predictable release cadence for major releases and maintenance releases.
How contributors operate
New features that intend to go into the next release are initially announced and discussed on the xen-devel mailing list. There is also a monthly community call to raise issues and discuss bigger development items. Invitation to the call has to be earned. If you are planning to implement a feature it is good practice to follow this convention, as otherwise you are running risk that somebody else could have started implementing a feature, when you decide to do so.
How we create a roadmap
The community nominates a release manager for each release. During planning and development of a release, the release manager sends out regular requests to the xen developer list and asks developers whether they have items to be tracked on the roadmap, asks for status updates, etc. The release manager, will however never add a work-item to the roadmap without a developers consent. Besiders sending regular updates to the list, we mirror the information posted on the list on the wiki and publish regular updates on the blog.
Users can request and vote for feature via Xen on Uservoice. For more information, see The Xen Project on Uservoice.com. Although there is no guarantee that an individual or vendor will step up and implement a feature request, a feature that is frequently requested is more likely to find an owner who is willing to implement it.
The Xen developer communtiy aims to release Xen releases at approximately 9 months release cadence.
You can find more information on how the Xen community manages maintenance releases on the following wiki page.