Well either way I hope they drop it soon (i.e this year).
Keep MP behind XBL, and then add value to the sub with GwG and the original TV programmes. Although, I highly doubt they're making the the latter free to view, but it again would make the most sense.
I don't see a problem with MS offering some exclusive apps behind Gold. I again point to the ESPN app. there is no equal on any other platform, so you can't claim its an app that is free elsewhere. It was built from the ground up as an exclusive Xbox experience. If an app like that were to remain behind Gold, I would be ok with that.
So all they need to do is open up the Xbox app store so that developers can publish any app (paid or free) without requiring Gold. Then MS can still make special partnerships to secure the creation of exclusive apps that they turn around and offer as a perk for Gold.
Think of it like they are treating indie games with the ID@Xbox program. A game developer can choose to make use of that program and not be locked to one console (and they don't have to require Gold if its a SP game and then the exceptions for FTP games, etc) or they can partner up with MS to create an exclusive title. If MS starts treating regular app developers like game developers, then that seems to solve all the problems.