Given the current prices on BD players and discs, the door is wide open for a new format to come in at lower prices. Using existing technology, as HD-DVD does, is a logical step.
The big question is whether anyone has the cajones and the cash to take on the Sony/Panasonic monopoly, and the studios who are demanding BD profit margins. Profits on a DVD movie are much lower than on a BD disc, so the battle is in getting the studios behind a format. So, any new format will need to offer improved profit margins over DVD.
I think that in a year’s time, if BD is still languishing WAY behind DVD in sales, we’ll see a shift towards a new format, but it won’t surprise me if it’s NOT an optical format.