Not January - waaay too soon. Probably in a couple of rev's time when they've recouped the R&D expenditure on the new process by using it for the most popular models - then they can bring the whole line up into parity.
I think the MBA will get a glossy screen by MW and maybe an optical drive, just maybe, to increase MBA sales?
I find it interesting though, since the MBA uses the unibody and it has been in the market for almost 1 year, how come no one comment on the MBA is using a new manufacturing method? Its like this news goes under Apple bloggers radar