To be completely fair, Oppenheimer spelled this out quite explicitly in the conference call:
1. We can't make the iMacs fast enough, and if we had been able to, we would have sold about 1M more.
2. There were 13 weeks in the quarter this year, compared to 14 weeks last year. We sell an average of 330,000 per week.
Bottom line: without these two factors, Apple would have sold exactly as many Macs as analysts had predicted. Today, we've gotten news that production problems have finally been resolved and that supply should improve over the next few weeks. If that actually happens, then we'll know the truth.
On the long-term future of the iMac, I'd say my colleagues are premature on reports of its demise. But I'd bet good money that this next Mac Pro will be the last one ever produced. You want to talk about a computer "nobody" needs anymore, that's it. Thunderbolt and other factors have rendered that machine incredibly niche now.
The iMac I think has a number of good years ahead of it. Yes, the iPad is supplanting it as a consumer desktop, but I think it has quite a bright future as a pro-level workstation -- essentially replacing the Mac Pro.