My guess is that Biden will come out with the plan to calmly attack Ryan and try to get him flustered. Once Ryan withstands the inititial assault, Biden will become frothy at the mouth and start spitting out some of the doozies that we all know and love. GG
Biden will want to attack Romney instead of Ryan, directly. He'll say early and loudly to the audience that while Romney told 70 million Americans that his healthcare plan would cover people with preexisting conditions, Romney made it known after the debate, to a few reporters, that he was mistaken and his plan doesn't actually cover people with preexisting conditions.
With Ryan, Biden must make him own up to the Ryan plan and let the American people know exactly what that is all about. Particularly saying goodbye to the homeowners tax credit and ending Medicare.
So attack Romney all night and when you deal with Ryan directly, do it factually and be careful of tone when addressing Ryan as Biden must not make him sympathetic. But let loose on Romney. Call him a liar directly and often. Ensure you bring down Romney's performance in the previous debate by pointing out over and over again the number of lies that he told.
Having said that, I'm pulling for Ryan to destroy.