I agree, prior discussions on the mailing list have been unable to resolve this though. There are two directions in which to progress:
1) Convert the project to be primarily about the federation protocol (which was the original direction of FedOne), with the existing client being a 'demonstration' implementation of the protocol. This sets our market to be other developers.
2) Be client specific, extend the existing client, add mobile support etc. Setting our market to be users directly. 'The next communications platform'.
(2) is what we have been mostly doing for the last couple of years, but our Java6+GWT+Ant+Subversion (only recently switched to git) stack was failing to attract new developers. There were several calls to rewrite the entire thing in (say) javascript.
There has been some work on integrating Wave with email (initially as a way of using Wave as some mailing-list replacement tool). See WAVE-70 (https://issues.apache.org/jira/browse/WAVE-70).
Chat integration is arguably simpler - and Wave already understands XMPP (for federation), so it would be possibly to map Jabber -> Wave (say). How you would want to map from Wave -> Jabber is more complicated (as any blip at any point in the tree, can be edited at any time, by anybody)...
You are correct that we have been incubating since 2010 - the community around it has changed quite a lot since then though...
There is no roadmap, as we do not (yet) have a large enough consistent amount of developer power to benefit from one. Most of the patches we receive are fixes/improvements that benefit the submitter (e.g. full text search, monogodb backend, etc.)
Sorry about the downloads page, you saw the page as prepared for an actual release - I have rolled it back to showing the last release candidate presented on the mailing list.
(2) is what we have been mostly doing for the last couple of years, but our Java6+GWT+Ant+Subversion (only recently switched to git) stack was failing to attract new developers. There were several calls to rewrite the entire thing in (say) javascript.