I don't care much what they do with MBAs, or advertising for them.
I do think it's likely part of Apple's or SJ's plans. The next gen or the following gen of the MB/Pro lineup should confirm it - local storage is 'too cheap,' and without recurring fees, and some people want smaller and smaller. Solution - solid state devices that are fast and thin, but completely non upgradeable. Take an Air, make the screen a dockable 'big iPad,' near zero moving parts, and store the majority of your 'data' between App Store (coming soon, download and run on demand, perhaps?), iTunes, and iCloud - all completely convenient, especially with multiple devices. Add in a universal binary format across iDevices and OSx/iOS, and buy once, run anywhere, as long as Apple stores it and you pay for the privilege.
The next gen may only be partway to the above, and it will be interesting to see two things:
1. timing and public perception/'readiness'/how many want it. NeXT systems were pretty damned neat, arguably maybe Lisa was too. Way too much $, and wrong timing, but a subset of the computing population loved 'em, just not enough to make the company an overall success. Apple has momentum, and can probably pull off a few things other companies would fail at (although I don't personally consider Apple TV a big success), but:
2. If they do go down a path similar to the above, everything 'in the Cloud,' possibly non-upgradeable devices - it's entirely possible the 'new' devices will appeal to enough people to make them successful, BUT if they remove the 'traditional' devices or go too far (MBP - user can add RAM, HD, have a lot of local storage, use off of a network, etc), they can alienate a lot of existing OSX fans, and simply replace their 5% or so laptop market with a different mostly non-overlapping 5% (possibly more). From a profit standpoint, it makes sense, but from a company loyalty one, not everyone may drink the Kool-Aid.
Here's hoping they don't force 'convergence' and the cloud as the *only* option, at least for some time yet.