mattur - 4:57 pm on Oct 7, 2010 (gmt 0)

As it is backward compatible with both HTML and XHTML syntax, does that mean it solves the problem of using XHTML output (from framework or CMS) when you cannot use application/xhtml+xml?

Yes, XHTML-style tags are allowed in HTML5.

So you can use <img> or <img/>, etc in a HTML5 document, both are conformant.