XHTML 1.1

I came across a document at the W3C which says:

This document summarizes the best current practice for using various Internet media types for serving various XHTML Family documents. In summary, 'application/xhtml+xml' SHOULD be used for XHTML Family documents, and the use of 'text/html' SHOULD be limited to HTML-compatible XHTML 1.0 documents. 'application/xml' and 'text/xml' MAY also be used, but whenever appropriate, 'application/xhtml+xml' SHOULD be used rather than those generic XML media types.

I should have known...

When I put in the correct MIME type of application/xhtml+xml for the web documents on uwto.org, and renamed the extension to .xhtml, I found that some pages wouldn't display because there were some markup problems and the pages were being processed as true XML, rather than HTML 4 "tag soup".

The thing that keeps me from going totally with XHTML 1.1 right now is another article

which states that Google doesn't have the capability to index .xhtml page yet. This article was created before Google updated its index to capture 8 billion documents, as of November 10, 2004, up from 4 billion.