One of the regular contributors to Digital Planet last week has reported overhearing Terry Gilliam admit that in the new HD version of Brazil you can see the wires attached to the actors in the flying scenes.
Bigger and sharper are indeed not always better. Back in '03 when I went to see The Matrix Reloaded at the IMAX with Baksheesh I remember fretting about how distracting the zits on Keanu's chin were in his dialogue scenes.
A few evenings ago I followed Frode into the HMV store in the Trocadero and he eventually pulled up in front of the small selection of Blue-ray titles. Not only is the packaging really awful compared to low-def DVDs, they seem to have gone out of their way to release only the most forgetable movies of the past decade. (I noticed that several had John Travolta in them...)