Apple says it’s learned a lot about making mobile devices smaller by building the iPad. The lessons have been applied to a pair of new MacBook Air models being sold at prices from $999 to $1,599.

Newest to the party is an 11-inch version of the flash-memory laptop, the smallest notebook computer Apple has ever introduced. This computer weighs 2.3 pounds and delivers 5 hours of wireless Web use; the larger 13-inch model adds 0.3 pounds and runs 7 hours on a single charge.

It's mostly battery inside the Air

Most of what’s inside the new models is battery, which makes them identical to the iPad in that aspect. These computers come with no optical drive (DVD) or hard drive, so installing any existing programs is going to be a matter of using an external drive for older programs.

The top end of the notebook line in the Air only has 256GB of memory, a wee acre indeed compared to Apple’s desktop line or even its latest generation of MacBook Pros. But the Air has extended its storage, gone greener and more power-savvy, plus slimmed itself to iPad size.

You can configure a device on the Apple Store that will push the top end of this notebook line beyond $2,000 — Apple wasn’t talking about a processor speed upgrade that adds $200, or the really-necessary AppleCare contract.

Sales of these MacBooks start today.

The big idea behind OS 10 release for next year — Lion — is that it shares technology Apple has polished for the iPhone and iPad mobile devices. “That’s what it’s all about,” said CEO Steve Jobs. “Mac OS 10 meets the iPad. We’d like to bring it all back to the Mac.”

The CEO peeks at Mission Control

Apple will bring applications to Mac users though a Mac App Store. There are two crucial elements in this model: Apple is taking 30 percent of each sale through the Store, a cut that comes out of developer pockets. But there’s extra sales traffic to offset that. Then there’s the automatic install and organization power of the Mac App Store. Anybody who’s tried to install an Adobe app might buy into the App Store to avoid that pain.

It all runs through an interface demonstrated as Mission Control. It will remind the Mac user of Expose and Dashboard and Spaces, but better integrated — and controlled by multitouch gestures on Apple’s Magic Mouse.

Apple plans to put out the Mac App Store first, within 90 days, for any Mac user who’s using Snow Leopard. The vendor is taking applications for apps right away. Lion is set for release in the summer of 2011, or as Steve Jobs said, “this summer.”

Lean Steve leads into iPhoto

You must use Safari, apparently, but it’s been place online at http://events.apple.com.edgesuite.net/1010qwoeiuryfg/event/index.html. Tim Cook, Apple COO, announced that the Mac installed base is now 50 million users, and the Mac has outgrown the market for 18 quarters in a row. Apple’s Mac business — not the mobile iOS units — is already $22 billion a year. Apple claims to have a 20 percent consumer market share for PCs.

The first 10 minutes of this event provides accurate ammunition to prove that the Mac tent is getting large enough to justify a switch away from Windows. “Whether you look at the products, or the numbers, or the products behind the numbers, the momentum has never been higher,” Cook said.

New themes for slide shows

Then comes the new iLife demos, starting with iPhoto. Phil Schiller, Apple’s VP of Marketing, is showing off “Full-Screen” interfaces for the app. iPhoto now makes slideshows automatically, an aspect that can be used for marketing presentations in lieu of the everyday PowerPoint decks.

There’s also an extended look at the new, more powerful editing features in iMovie. It’s hard to describe how much this program has improved over the last two years. The trailers shown look Hollywood-caliber, using included music and effects. Frankly, iMovie became an embarrassment about three years ago, but Apple has rescued it and driven its capabilities much closer to Final Cut Express.

As always, during a major Apple event, the company’s online store was taken offline so the new products can be unveiled for sale afterward.

Over the first 30 minutes of the Apple event, the brief on the Mac business state and the two most visual iLife apps dominated  the stage. iMovie has credits now, storyboards, themes to speed up editing. If you’re using a Mac to create marketing materials, these are marked upgrades to the apps which Apple ships for free with new systems.

Which might be the point here — selling the new systems over a holiday season is going to be easier with this included software’s new features. Apple will be selling the iLife ’11 package for existing Mac users, too. In a real upgrade to the value of these apps, existing users of iLife won’t have to re-purchase the product as we have in the past. There’s a $49 upgrade. Previous versions sold for $79.

There’s no update at all for iWeb and iDVD that is worthy of a demo in the conference. The former never had the simple-build ability for websites in its early releases, and later updates came after the blogging habit replaced a lot of websites with WordPress blogs. iDVD works well enough to burn movies built in iMovie, but the latter’s enhancements seem to have frozen any improvements on iDVD.

GarageBand got a nice demonstration that shows massive editing improvements for the tool we use to create podcasts, one of the most cost-effective marketing and customer-outreach tools. The Mac’s included software make it dead-simple to build podcasts with GarageBand. The fact that a six member band can better mix its music is nice for your off-hours, unless your business is producing music.