I want to chime in that I too have been unable to log in, for two days, so far. As a professional software developer, I try to avoid debugging other folks software in my spare time, so I haven't done more than attempt to log in.
As a past and potentially future customer, I'm not impressed. When log in procedures change, it's generally a good idea to inform the affected parties of the details of the change. An e-mail and/or web site splash page seem appropriate. Also, unit testing with end users on a production system rarely works out well. Development environments exist for a reason. Finally, when a production problem is identified by your customers, it should be corrected as quickly as possible. Two days for a problem of this severity is too long.