I notice that a sign of a winning campaign is when the media does not know who the running mate is before the announcement. I remember the media knowing for certain Paul Ryan to be the pick in 2012.
No. Nobody expected McCain to pick Palin, and Biden was talked about as one of two or three possibilities for Obama.
True, but even though Biden was ultimately picked, it seemed like the media had Evan Bayh as their "front-runner" for the VP slot. I kept seeing rumors about him pop up more than Biden. Anyhow, I see what you're saying. It's a good point.