Going back to the Civil War imagery that connected so well with fans during the Hitchcock Era, the new catchphrase is "Join the Battle".
All things considered, I like it. Quick, simple, actually ties into the team's background, and calls out to the fans to identify themselves with the team.
Aside from the bad grammar, one of the worst parts of "Gotta see it live!" was the way it reduced fans to mere observers. It detached them from the game and seemed to provide a level of distance. With "JTB" (hey, it even makes a nice hashtag for you!), you invite the fan to identify with the team again, and make it clear that support from the crowd is important. That call to take part also helps to include fans outside of the Columbus area who follow the team online or over the airwaves, and helps to bring the "community" together.
That said, as much as I like this, I suspect a lot of fans will wait to act on these marching orders until they see just who the team is asking them to take the field with.
If Scott Howson cannot deliver on his promises of reshaping the team - especially by the end of August, when All Star Game tickets must be officially bought and paid for - I suspect that quite a few fans will be content to watch the fight from the sidelines until given a reason to get stuck in.