So I just made use of the new policy to do something I wouldn't have been able to do before, and have to say I'm really pleased:

Yesterday afternoon, I was checking in for my flight to fly ewr-sfo today (Saturday) on an afternoon flight. I had original scheduled for saturday because I didn't know what my friday schedule would be, but now I was done with work and really just wanted to fly as soon as possible.

On doing OLCI, there was an option for "other flight options." Clicked it, and the option to fly Friday evening for $25 came up. Switched the flight, paid the $25 online, got upgraded a few minutes later, and had a nice ewr-sfo flight in F a day before I was scheduled to, all for only $25! ^