This has been happening to me too.
The odd thing about this happening to multiple people at the same time when going to different sites is that as far as I know, the default browser is not supposed to proxy through any other host (as Opera does). So there should be nothing that different users going to different sites have in common that would cause all of our browsers to start crashing at the same time. Unless:
a) The default browser really IS proxied and all our traffic is going through some server somewhere, which is malfunctioning lately.
b) There's some kind of virus going around which is causing browsers to crash.
Anyone have another explanation?