No sooner has Apple set forth its new MacBook Air 11- and 13-inch models - and killed off the original MacBook range - than it is working hard to bring its MacBook Pro line-up into the ultra-thin age of notebooks. At least, that's what the rumours would have us believe.

Sources, as sources are want to do, have told MacRumors that the tech giant is already working on a 15-inch super-skinny MacBook Pro. While others have informed TUAW that Apple is also looking at releasing a 17-inch version, thereby covering all screen sizes.

In all likelihood, the gossip comes because the future of solid-state drives (SSDs) is rosey, with manufacturing costs of the devices plummeting. Plus, the Cupertino giant has already made a stance against optical drives with its Air laptops, the creation of the online Mac App Store, and releasing OS X Lion over the 'net and on USB stick only.

None of this is particularly surprisingly, however. What is less realistic is that MacRumors sources tell it that these new machines could even be unleashed in time for Christmas. Seeing as we've only just had a MacBook Pro refresh, we seriously doubt that there'll be another this year. It doesn't fit in with Apple's "way". After all, what did happen to that 7-inch iPad rumoured to come out last Christmas?

What do you think? A thinner MacBook Pro for 2011? Let us know in the comments below...