I jumped over to David Hyatt's site again to see if any other comments were made on the IE rendering malformed issue to find a clarification on his comments. He states that his comments were on XML, not HTML.
I admit, I jumped the gun on this one just like 98% of everyone else, but Mr. Hyatt could have chosen better words, especially when stating "If we lived in a world where browsers could refuse to display malformed content." I, as well as most other people, took content to mean HTML. Sorry, David.
I do, however, agree with him (now that it is clear of what he is saying). There should be no excuse for malformed XML, and any parser should refuse to display malformed XML. XML is based upon strict structural rules (just like any programming language). We expect perfect C#, C++, VB, Java syntax; why should we allow malformed XML?