Vex has moved from being a component in the WTP Incubator project to being a project on its own in Mylyn Docs. Like all other Eclipse projects Vex has its own home page: eclipse.org/vex. Our project lead is Florian Thienel, currently the 99% of Vex (only you can change this).
Last week milestone 8 was released. If you already use Vex then you have to migrate your vex-plugin.xml files. Otherwise you should give Vex a try to edit XML files word processor like.
The next big thing is XML Schema support in addition to the good old DTDs. Already 1.0.0 M8 contains basic support for it. At the moment you have to register the XML Schema manually by editing the vex-plugin.xml file – the UI to do this is under development. So stay tuned. Vex is moving forward slowly but surely.