Before Lester got noticed during the World Series and people started talking about it, I don't think the general public knew that this was commonplace and accepted by the players, even though technically against the rules. I know that I certainly didn't.
The two Pineda incidents, and especially this last one, has brought this out front and center.
I think MLB has to address it now, somehow. If even the hitters are condoning it, and some of the comments that I heard over the past couple of days is that they WANT the pitchers to be able to properly grip the ball, my guess is that the rule will be relaxed or modified in the near future, possibly even within the season