Even with blagging edu discounts on this side of the pond, they're still pretty steep. But Apple seem to have nailed getting the right price point to max out PR impact and lowballing spec of said boxes so you're looking midway up the chain... by which time the fanbois are sold no matter what cost ;)

I'm teaching a mobile computing course this term. I've got the students
developing Android apps as it's simple and free. I would have liked to
let them loose on iPhone as that's obviously 'sexier', though I doubt
there'd be any learning advantage.

Get 'em inspired innit. I've been out of that game for a while, but isn't Android an OS platform? Also, nice way to get 'em to critically reflect on the different industry models (FWIW - the mobile final year course I was involved with a few years back split in to two - one more apps/dev based, t'other focused on business angles (in the broadest sense - more 'apply the stuff you're able to code wrt your audiences/platforms) - and I can imagine there's more scope than ever to compare/contrast from all these angles).

Your point 4 is interesting. Tablets were first developed at Xerox Parc
in the late 80s as part of their work on Ubiquitous Computing. Their key
realisation was that computing should be "calm" and I think we're only
just beginning to experience this with devices like iPad. Mobility is
just one aspect of this, in many ways just the start.

PARC always had the best ideas. Apple's just about hit the jackpot for mainstreaming most of 'em.

Incidentally, on this side of the pond, it's gonna be interesting how RIM/Playbook will pan out. Android's the biggest-growing mobile OS on smartphones. And I suspect Nokia/MS is toast in the mobile space.