Barclays Capital has cut back on the number of PCs it thinks will ultimately move this year on the theory that the iPad and its ilk will eat into PC volumes.

It thinks that 15 million tablets will be sold this year - and with Europe stalling - PC growth will drop from 21% to 19%, with notebooks making the sacrifice. It's figuring a 30%-40% cannibalization rate in netbooks and low-end notebooks and giving Apple 70% market share at the expense of Microsoft and Windows.

Intel is also supposed to lose business to ARM and its followers.

Sanford Bernstein's star analyst Toni Sacconaghi, usually a level-headed guy, came up with some back-of-the-envelop calculations that Apple could sell upwards of 25 million iPads in fiscal 2011 though given all that could happen he's estimating 18 million but "we do not have high conviction in our estimate." It might be utterly unrealistic.