This would allow us to modify some elements in particular forms by overidding the form() method and checking the name. I've done it for my site this way:
In function main_parts($content), I've simply changed this
elseif (strpos($key, 'form')===0)
$this->form($part);
to
elseif (strpos($key, 'form')===0) {
$this->form($part,$key);
And added the key parameter to form($form) which became form($form,$formkey=null).
Since this method is called at some place, the null ensures compatibilty with other versions.