A quick Xtags demo has been released!
The current (very buggy) version supports Markdown, BBcode, Geshi and smileys parsing. The smileys look pretty cool!
Geshi was very hard to integrate - and I am still not happy with it. Once I've cleaned up the code, sorted out all the smiley configuration, fixed Geshi integration (properly) and added MediaWiki parsing I'll give it an initial release!
For now enjoy the demo! http://www.errant.me.uk/xpress/demo/xtags/