I don't think the gameplay will
totally different, but we'll see where it goes. 2nd will be to swing, and the arrow keys will be used to move the bat around when batting. I haven't fully thought out the pitching engine, so I won't say how it's going to work yet.
I don't think there will be baserunning becuase there won't be any fielding/defence. I think it will become to slow and bloated if I try to create an AI that decides where to throw it based on where the ball is on the field and where the runners are (although because I used to play baseball for my highschool, I do have a good understanding of what all the situations are, so I could possibly hard code it in). There just seem to be too many combinations and possibilities that it would slow the game down too much. But we'll see.
Haha I doubt I'll do named players.. Actually I think I will. I'll use Celtic2 to extract all the names and put them in their proper places, and I'll use the rosters from last year (which means I'll be using MLB teams ;)

) But there won't be any player abilities or anything, so it will just be a name.