Rams owner bought 60 acres in LA, then he leaked to a media member that they would be moving to LA after the season but weren't going to make the announcement until after the Super Bowl. Basically, he is just using LA for leverage but also as a last resort if taxpayers don't pony up for a new stadium.
The Raiders aren't being quite as aggressive just yet. They simply hired a direct mail company to send some surveys to a small percent of San Antonio residents asking them questions about whether they would support the Raiders. Really, this was a much cheaper way to put the rumors out and get the ball rolling towards a new stadium deal in Oakland.
My prediction it will all be the same next season except a couple teams will be getting new stadium deals. Next season the rumors of a team moving to LA will start up again when a light bulb goes out in one of the other stadiums around the league.