I actually have a good feeling about the outcome of this and the use of the Slingbox in general. If MLB or anyone else has lawyers who's job it is to represent their client, they will not proceed with a lawsuit, and from reading the link above I am more convinced of that.
Your own personal use - wherever you are - will not be made illegal. If you are legally receiving the signal then you could be anywhere to see it. There are other ways to do the same thing, even as rudimenary as a cam on your computer, or other similar boxes to the Slingbox. Then there is the WinTV USB that simply plugs into your USB port and can receive over the air or Satellite/Cable TV. It then can be recorded or sent over the internet.
I really believe this is where companies have to realize technology is going to win, rather than fight it, join it.