>Are you referring to VS2008 SP1? Can't say that I've noticed much difference when opening an ASPX page in the designer. OTOH the delay when displaying a page using the 'View in Browser' option seems to have actually got longer on my machine :-{
The version I have is 9.0.21022.8 RTM. I never use View in browser. So, as for that option, I cannot tell.