Remember all that stuff I said about how we already have an end-to-end security solution that ensures that users are connected to the right web site and that there's no eavesdropping going on? Well, you can scratch all that.
I knew there was a User Experience problem with SSL in that most people ignore that it's happening and therefore don't notice when it's not happening. I also knew that there are known potential attacks on SSL, but it seems there's a newly discussed renegotiation problem that makes the whole system seem suspect. This posting from RSA does a good job at providing an explanation.
This is a big deal. SSL really IS web security. So many other security solutions rely upon it -- assuming that communication is safe and secure because it's done over SSL. Even if all the major vendors get a fix out tomorrow, we'll probably see this problem around for years to come.