Bert Bos raised this issue on the telecon of 2012/04/25. I'll add in a link to the minutes once they're posted.
His proposal is to not allow elements in HTML to be styled as regions. He prefers creating and/or using other mechanisms for generating region boxes.
bert: request for notes:
... we should move out the things we /don't/ want
eg the idea of elements being a region
... need a note saying that regions won't be created like that
bert: I want to disallow
bert: no redundant elements should exist in a web document
related comments from the telecon:
stearns: that wasn't the resolution
... we never decided to disallow it; just discourage it
glazou: don't want to disallow either
minutes here: http://lists.w3.org/Archives/Public/www-style/2012Apr/0757.html
You can search www-style for the bug number for the discussion of this issue over the years. My latest summary of the reasons why this issue should be closed with no change is here: http://lists.w3.org/Archives/Public/www-style/2014Jan/0090.html
The working group resolved to close this issue with no change.