I think if it was easy, they would have invested already. Old games can be rather niche already in some cases, and having a card that supports it only further narrows down the market.
That said, there are certain companies (coughrockstarcough) who are such prolific re-releasers of older titles that they would definitely feel threatened by the tech.
That said, there are certain companies (coughrockstarcough) who are such prolific re-releasers of older titles that they would definitely feel threatened by the tech.