I'll add, pds...
I think the Keynote, thought I haven't watched it yet, was good -- the new MacBook Air is what the Air always should have been (and that's not to take away anything from the last Air), and now it's priced affordably for everyone. It's a good machine with good specs, and even the 11" Air is snappy and responsive for everyday tasks... of course it won't encode video like a bat out of hell, but it will encode video. It won't handle your 542-layer, 6.4GB Photoshop file, but it will run Photoshop, and usably.
With the all-SSD configuration, Apple is clearly trying to mimic a more iPad-like experience on a Mac computer with it's near-instant wake time, and simplify downloading and installing apps.
That last point carries more weight and is very "freeing" to most. I'll explain.
My wife has a MacBook Pro 13". It's awesome. I'm stuck with an older, polycarbonate, white MacBook from 2007 that can't be upgraded any farther... but I digress. So my wife has this MacBook. She discovered Skyping with her mother in California (we're in Texas) via Skype installed on my "work" Mac mini on her account and fell in love with videochatting. So she goes and installs it on her MacBook Pro, and all is well. I used the computer once (I rarely use her computer) and noticed that she had successfully dragged Skype into the dock for quick-launching, straight from the mounted DMG image. The DMG image was still even mounted on the desktop (and I used the computer weeks after she installed it).
While it may seem like a trivial, forehead-slap experience, I'll bet that this happens a lot more than people admit. My wife also has limited (from a technical standpoint) but functional experience and knowledge about the underlying filesystem... music is accessed through iTunes (which automatically organizes the underlying file/folder structure), photos and digital camera dumps via iPhoto (again, filesystem organized for you automatically), and then eMail and the web.
Point being that a casual Mac user, which there are a
lot of, rarely accesses the filesystem on a daily basis. It's slowly being hid from view, which, from a techie's standpoint, can be either a good or bad thing. But Apple's not yanking it away from us -- they're simply providing alternate options, just like they did with iTunes and iPhoto removing the need to manually organize a file structure... but with iTunes and iPhoto, you can manually organize if you like. Now they're doing it with applications...
...so they don't stay on mounted DMG files, or copied to the home folder instead of /Applications accidentally, for example.
It's perfect for my wife. Not only that, but it takes care of updating the apps, too... another thing my wife doesn't prioritize with her MacBook Pro. Plus, you get to use the app on ALL your Macs that belong to you, instead of having to purchase individual licenses for each box you want to run it on (like Adobe and Microsoft products, among many, many others).
I also believe that Apple isn't, in any way, trying to take "total control" over our desktop and laptop Macs -- they're simply simplifying the experience even more by offering an alternate and easy way to purchase and install applications for the Mac, mirroring the seamless experience one has with an iPad or iPhone/iPod. Developers will still be able to distribute apps the old-fashioned way: download a "demo" program from their website, mount the DMG, copy the application to /Applications, unmount the DMG, launch the program, visit the developer's website again to purchase the software, open Mail to receive the email with the registration keys, select "Register software..." from the app's menu, copy-paste the serial number, then finally unlock the app... you know...
that glorious experience. Easy for us -- convoluted at best for a casual, non-techie Mac user.
My only gripe is it feels like Apple announces things a lot farther ahead of time these days, making the wait for 10.7 all the more distant.