I wouldn't hold my breath. Apple has a nasty history of not enabling things like this for "old" hardware, even though there's no reason other than marketing for them not to do it.
They used to be a lot better about it; the original 5th gen iPods got game support and gapless playback when the 5.5 gen came out a year later, and earlier iPods had podcast support added to them via firmware updates when podcasting became a big deal. I remember they also used to add new features during point upgrades to the OS rather than just "bug fixes," like one point upgrade for Panther that added support for WPA if I remember correctly.
A couple years ago they added 802.11n support for some notebooks that didn't come out of the factory with the software to enable it, but they charged $1.99 for the software update.
Then there's the iPod Touch - Apple charges for software updates for that.
I seriously doubt Apple is going to issue a software update for the "old" (7 months is "old") MacBook Pros for the four-finger gestures. Other than simple customer satisfaction, they have no reason to do this
they can just as easily argue that the Pros didn't come with this functionality out of the box, so you haven't really lost anything by not getting the new features of the new machines (even though the 17" model hardly qualifies as "new").
Personally, I'd even pay $1.99 for updated multitouch for my Early 2008 MBP. Even so, I don't see it happening, in which case I have a one finger gesture for them
