It appears that the iPad processor is based not on the new Cortex A9, as everyone assumed, but on the older Cortex A8.
The A4 and the A8: secrets of the iPad's brain
There are a few Cortex A9 based tablets which should be coming out close to the time of iPad's more expensive versions, so I'd guess this is one more stick for the competition to beat the iPad with.
The use of the older chip may explain the multi-tasking thing too.
I suppose iPad v.2 or v.3 will have a more modern processor, and probably Flash.