<blockquote>@orkel I observe no differences: http://jsfiddle.net/NAAP8/1/</blockquote>
<code>$.domManip</code>? What you trying to show here? With that code you will not observe any difference, because it's not different from my example. You have try it with your code – http://jsfiddle.net/Tec2k/ 

<blockquote>breaking change for some oldIE edge cases</blockquote>
This is not a breaking changes for oldIE edge cases, this is breaking changes for oldIE. There is no "edge", you quite literally breaking
DOM manipulation in IE6/7 for tables.