I’m firmly in the XHTML2 camp - it’s a better technical standard, regardless of browser support.
You clearly haven't read either spec, or, if you did, you don't know how specs work good enough. XHTML2 is not a good spec technically. Lots of things are utterly undefined.
XForms is a good spec. It only lacks a clear migration path for authors and changes things from XHTML1 for no good reason. It also can't be used in text/html which is what most authors use.
BTW, this is not about HTML vs. XHTML. You can use HTML5 as XML (called XHTML5).
