This makes sense to me. I suspect that a lot of people with basic computing needs who would have bought the MB in the past are or will be buying an iPad instead. For many of those who need or want a basic laptop computer, the base-model MBA will suffice, assuming it has a 128 GB SSD. The new Sandy Bridge processor should be plenty fast enough for most tasks. For those who want an optical drive, there's the $79 external Superdrive. For those who also want more storage, there's the 13" MBP. Yes, there are people who will want the exact feature set of the MB at the current MB price point, but there are plenty of feature-and-price-point combinations that people want, but that Apple doesn't offer. The question from a business standpoint is how many people who want the current MB at the current price point would buy a Windows laptop if it weren't available, as opposed to buying a 13" MPB, a MBA, or an iPad. I suspect it wouldn't be enough to warrant keeping the MB in the line-up. Dropping the MB would also be consistent with Apple's approach: make the consumer products lighter and thinner, and drop features that Steve believes are on their way out (e.g., optical drives and HDDs).
My 2008 15" MBP still handles everything I throw at it, which includes all the basic consumer tasks and a few prosumer tasks, such as digital photography. I normally use it with an external monitor, keyboard, mouse, and variety of peripherals connected to a USB hub. If it were to bite the dust after the MBA refresh, I'd probably replace it with an 11" MBA with a 256 GB SSD, assuming I could connect all my peripherals -- and, yes, I'd buy the external Superdrive, because I still rip DVDs and CDs. I love the 11" MBA's ultra-portability, even though my MBP rarely leaves my home office, now that I have an iPad.
I'll see everyone back at this space in about three years, commenting on the article, "Apple to end-of-life MacBook Air, now that iPad 5 fully supports externals peripherals via Bluetooth and Thunderbolt?"
