From the BBC F1 site:
We will not be able to provide F1 coverage in high definition this year. The BBC relies on Formula 1 Management (FOM) for the provision of all of its live pictures and as such the broadcasting of high definition pictures is dependent upon whether FOM uses HD cameras or not.
That is just so typical FOM - plonkers. F1 is supposed to be the pinnacle of technology and engineering and they don't even bother broadcasting it in HD?