That's when cloners come in and beat the living daylights out of them by copying and improving upon their innovation.
There's a fantastic book on this, 'Copycats':
http://www.amazon.com/Copycats-Smart-Companies-Imitation-Str...
Incredibly well-written for a HBS book, lots of solid case studies, and some interesting research into the nitty gritty numbers behind innovation vs imitation.
I'd like to add that maybe one doesn't need to be obsessed with inventing something new or fulfilling an unmet need.
Sometimes you can just copy and do better. For ref: http://www.reddit.com/r/Entrepreneur/comments/2d51zq/why_do_...
Great book about beginning with 'inspiration': http://www.amazon.com/Copycats-Smart-Companies-Imitation-Str...