This is not going to happen:

First, function call syntax is nicely parallel to parameter definition
syntax, and it is obviously not possible to define parameters named like
keywords.

Second, making exceptions like this leads to more exceptions and finally
inconsistencies. People will say "if it's allowed here, why not there
too, where it is grammatically unambiguous". Quoting the Zen: Special
cases aren't special enough to break the rules.


PS: In addition to what David Lambert and Matthew said, you could also
lower() all attributes on generation and use

xhtmlNode('div', Class='sidebar')