Probably not, at least not for Apple.

A large part of their profit margin comes from making only very few models that share commonality in parts. Nobody is screaming for an optical drive either, so I suspect that the old unibody laptops will only be kept around for 1-2 years until demand decreases.

There's bound to be other companies that will cater to that market, but they won't be able to ship OSX on their laptops.