Interesting data from the BBC: mobile + tablet requests on the iPlayer catchup service now outnumber all requests made on TV screens, via STBs, consoles, smart TVs etc.
Still dominated by PCs, as one would expect, but portable devices appear to be growing fast than devices that 'put internet video onto your TV.
Of course, this is partly because there are not many good solutions for doing this. The addition of Sky to iPlayer in the next few months will spike the numbers in other other direction. However, it seems quite possible that hand-held devices will take a big share of viewing - especially for the kinds of viewing that currently happens on 'second sets'.