There are many Cgi pro\'s and hobbyists who use render engines like FinalRender, Brazil, Maxwell etc. Those have been multithreaded code from start.
and with Mac\'s doing many Core2Duo units I\'m sure the whole Adobe suits will go towards multithreaded coding as well.
Like with the console industry ; add ons/ins, are going to loose in the long run.
What kind of consumer percentage wants to pay a jacked up price for an add in physics card, set by a third party, when software devs already go towards multithreading en masse ?