Do you think Wii will introduce new game titles for the Wii Balance Board in the future? or it is just solely for Wiifit...

it would be a waste just to invest on a wii board just 4 1 game...

Excerpt from IGN GDC interview with Reggie Fils-Aime:

IGN: Under $100 for another peripheral is still a chunk of cash to shell out. Do you have anything in line that will make further use of the Wii Balance Board?

Reggie Fils-Aime: I think what you're speaking to is, from a consumer perspective, help me feel good about this purchase. There are over 10 games in development that take advantage of the Balance Board. Certainly in terms of ongoing enjoyment, we believe that Wii Fit plus the Balance Board will provide that to the consumer.