As we have seen in the past month or so with BOTH HW world champions losing, the question has to be asked.

What happens if Frank Shamrock gets caught with a right hand and gets K.Oed?

I mean, what does he do? Go back into retirement? Look for another opponet?. WOuld it destory the legend of Frank Shamrock?

I think in this day and age that anyone can lose. This past weekend is a great example. I think its a bit more accepted and I think it would damage his rep but not as bad as if it were a few years ago.
Look at Carlos Newton, he is 11-7 and he is considered one of the best.

I think he will still fight. Frank isnt the type of person to give up.

see Sakuraba, Kazushi

He will be torn apart on internet forums and the like. He may fight again he may not. I think he will win pretty convincingly.

Would it be a disappointment if he won by decision?

The competetion is too good for anyone to stay undefeated for long anymore. I actually do think that a decisive loss is exactly what will send him back into retirement. He's no spring chicken and is in a tough weight class. Doubt he'll lose his first fight though, but it's possible.