I think there are negatives and positives either way.
If you continue to develop the product you have more control and the potential for controlling more revenue; however, as you say, you incur more risk.
If you license the device, you don`t have such an investment. Or you may have a device that appeals to multiple industries and would be difficult to bring to market by your lonesome. On the minus side, you won`t have much control over the revenue. Plus, it may be difficult to knock on the doors of a major company for licensing opportunities. Beyond that, a great prototype is just going to open up doors. So you still might want to consider that.
I generally side on the "license" (when possible) side of the equation. That`s just my personal opinion, because the "idea storming" is what I enjoy the most. There are always great ideas out there.
There`s a good section in the StartUp Nation book that covers this that explains it better than I can.
Hope that helps.
Or have I thoroughly confused everyone.
Matt
Mr. Solo,
Good luck. Am curious about your field and the product you are re-designing. It`s not golf, is it? I have just posted a message to try to get investors for some inventions. I want to sign-off/license quickly, but I understand your wanting to keep control/ownership, especially after having made a professional model. Years ago I spent years trying to hand-manufacture a few of my own things. Useful experience, but don`t want to repeat it.
Ray
One thing you should certain do, and that`s join an inventor`s group in your area. The United Inventors Association at www.uiausa.com can point you to a local group. Non-profit inventor`s groups are typically loaded with retired engineers and people who have gone through the process once or twice already. They can really help you move your project along. Good luck!
You should also check out http://www.score.org/
They offer free mentorship programs, and you can even hook up with someone who is familiar with your field. Since all their mentors have "been there, done that" their help is invaluable.
Is there anyone out there trying to start up a new business behind a new product or invention? If so, could you share your ideas and any triumphs or pitfalls encountered along the way. I believe learning from others experiences is very helpful, especially for those who are first to venture down this road. 
Years ago was working on making my own inventions in wood, forming a company, and marketing them. Now am shooting for licensing as early as possible. Stalled now by $; working on digging up an Angel. You may want to look into inventNet.org; also has interesting forum.
Best, Ray
Is there anyone out there trying to start up a
new business behind a new product or invention? If so, could you share
your ideas and any triumphs or pitfalls encountered along the way. I
believe learning from others experiences is very helpful, especially
for those who are first to venture down this road. 

Kathy,
A question for you, when it comes to ebay, would you consider that a good test market?
Im not trying to say you product isnt worthy on the contrary it may be beter than that what the ebay market has to offer.
IMHO I wonder if ebay is full of people looking for a bargoon and unless the price is right then they move on.. That is unless the product is very unique and not available in there area at all.
is this a false image that i have when it comes to ebay buyers??
mike
ps Id like to take a look at you product do you have an ebay link for me , either post it or please email it to me.