As someone who has used LHR as a pax since 1954 and continues to use it at least once a week I find myself wanting to agree with those who say that QB and T2 should be preserved - but I can't because actually there is so little of the original buildings left, or at least visible! If we want a meaningful Heathrow Museum then BAA are going to have to restore both buildings to their initial QB and Europa designs, and that hardly seems likely or practical anymore. I've realised that my nostalgia for all things aviation is over-ruled in this case for a desire to have a Heathrow of which we can be nationally proud, rather than the generally embarrassing dump that it now is (and I'm really sorry to find myself saying that, but anyone who travels the world a bit knows how true it has become).
My first real surprise at the "Heathrow East" proposals is how long it seems to have taken BAA to come up with the idea! Surely someone realised many years ago, when T5 was being designed, that there might be the opportunity to exploit a temporary overcapacity and undertake wholesale redevelopment of the CTA? My second surprise is that the plans shown on the BAA website don't include any reference to the proposed new runway; one might have expected the development control plan to have taken that into consideration as well.
Oh, and by the way, the Houses of Parliament that Guy Fawkes tried to blow up were demolished in the 19th century and replaced by a modern, up-to-date legislative complex - probably referred to as "Westminster South" in its day and the subject of much criticism at the time!