Apple touted some pretty decent battery life numbers at the new MacBook / MacBook Pro press event this week: up to five hours on the Pro with discrete graphics off, and four hours with it on (both surely assuming ideal low-power conditions). One of the things that didn’t come up at the presser, however, was that new MacBook Pro batteries actually have just under 20% less energy than their predecessors. While both kinds of MBP batteries are 10.8v, the old ones are rated at 5600mAh / 60Wh, while the new ones are rated at 4700mAh / 50Wh. (MacBook numbers updated below.)

I’d estimate that the integrated NVIDIA chipset and ever more behind-the-scenes power-saving techniques are why Apple is claiming such solid life despite killing a fifth of the machine’s energy supply — but a 20% reduction is still no small number. It also means that as your new MBP’s battery degrades, you’ll have a smaller pool of potential energy to rely on, meaning you could wind up having to replace your battery more often (although that’s a little conjectural, at this point).

But as some are now postulating, one technique Apple may now be employing to save power is making use of the machine’s GPU(s) to accelerate video playback. We already know that the new MacBooks have a different build of OS X than older gen machines (9F2114), but one thing I also noticed is that Quicktime, the engine behind Apple’s video encodes and decodes, was also revved in the new machines, now clocked in at 7.5.5 995.23.3 up from the last machines’ 990.7. With a little luck, perhaps video encodes will finally be hardware accelerated, too. (Will have to test that one later!)

Update: Matt at Gizmodo mentions that the numbers add up, when comparing the extra 20% battery life you get in new models using the integrated GPU vs. that same five hours claimed in old models using discrete graphics. Also, new MacBooks have also decreased battery capacity (as expected), from 55Wh in last-gen models to 45Wh.

Now look, laptops are a big deal. For most users, laptops more often than not represent one of the most expensive devices they own, TV aside — but unlike a TV, most people are apt to replacing their laptop every couple of years. And when it comes to product cycles for laptops, a couple of years is sometimes how long it can take to get one out the door: next week’s new machines probably got started shortly after the Air, likely in 2006 or even 2005. In other words, these machines got started well before we knew things would be headed as far south as they’ve gone.

So now that we’re neck deep in the worst financial crisis in decades, now that consumer spending is nosediving, now that hoarding is displacing buying, now that even high-flying VCs are getting nervous and battening down the hatches, I have to wonder: is this really the right moment for Apple to launch new laptops?

Probably not. Granted, there’s no turning back on a launch planned years ago, and people will always need computers (as long as the lights don’t go out, anyway). But the interesting thing is that Apple has an important new shot to make here: this is the most opportune possible moment for them to take on the booming netbook / lower-cost laptop market, a segment that will only balloon in size in the years to come as consumer spending continues to hemorrhage. The $2,000 pro market won’t go away entirely — but it certainly won’t be a growth area as larger numbers of buyers are starting to worry more about foreclosure and eviction than whether or not they can upsell for the ExpressCard slot and extra three inches of screen. Guess we’ll see next though; and hey, if nothing else, at least we can set all the doom and gloom aside for a few minutes while we geek out on Steve’s dog and pony show.

Update: Boot-up video hotness after the break, at the request of commenter Brad.

Also, to further clarify: Samsung SSDs are not available for purchase to end-users. I have one because I was sent it for review (see link above to Engadget).

To put that boot in context, it’s a fresh install of Leopard booting with a number of extensions / startup items in the back and foreground, including Quicksilver, TextExpander, Growl, and a few others. 20 seconds sure ain’t bad.