I weighed in at 90% and he thought it might be closer to 60%. According to last year's figures from the Office for National Statistics it was only around 73%, marginally closer to his estimate (though that figure must have increased to at least 75.01% by now).
I was fairly staggered - 1 in 4 UK homes are still not hooked up to the web. It puts arguments about changing patterns of media distribution and consumption into context and also demands that any talk of a digital media revolution is at least tempered with consideration that a very large minority of audiences are not currently party.
Another set of figures in the report lend weight to Prensky's emphasis on the generational divide in his natives/immigrants/dinosaurs theory:
The chart shows that a far lower percentage of older sections of the population are using the internet and also that a sizeable proportion amongst that group have tried and decided, cheers no thanks.
Finally the report also gives some raw data on usage of online tv and radio. The trend here clearly shows that participation is widening, but also that the rate of growth appears to be slowing. This perhaps hints at as yet unreached sections of TV and radio audiences who are either economically disenfranchised from the digital revolution or simply satisfied with traditional forms of distribution.
You can view the full report here and fish out a couple of stats to add weight to your own arguments about the impact of the internet on the media industries.