During today’s “Back to the Mac” event, Steve Jobs asked, “What would happen if an iPad and a MacBook hooked up?”

The new MacBook Air is the answer.

No thicker than 0.68 inches, the new 13.3-inch MacBook Air weighs 2.9 pounds. Battery life clocks in at 7 hours, with a 30 day standby time. It has a 13.3-inch screen, with a 1440×900 resolution, with no optical drive or spinning hard drive. Every MacBook Air will ship with an SSD drive.

Apple isn’t using a normal, off-the-shelf SSD for the new Air. Instead, this new notebook sports a custom flash solution, right on the logic board — just like the iPad and the iPhone. This means future upgrades aren’t possible on this machine.

The smaller MacBook Air is built around an 11.6-inch, 1336×768  screen, weighing just 2.3 pounds. It sports the same features as the larger MacBook Air — even the battery life.

Both machines ship with stereo speakers (new for the Air line), 2GB of RAM and NVIDIA GeForce 320m graphics.

The 11.6-inch MacBook Air starts out at just $999 for a 1.4GHz Core2Duo and 64GB of storage. Bumping up to 128GB of storage is an additional $200.

The 13.3″ Air starts at $1299 with 128GB of storage and a 1.86Ghz Core2Duo. Bumping to 256GB is an additional $300.

The new MacBook Air is available today.