I think it means a lot for Liddell. What if he gets stopped. Dana White will start bringing up exactly the same speech, "Chuck was the most famous..." I'm sure Liddell does not want to hear that speech AGAIN about the past especially when his former victim has returned and avenged the previous losses. No matter what some people might say, but it is still a humiliation. Silva vs Jackson is a good example. So in my opinion Chuck has nothing to gain here (well, maybe except for a nice paycheck) and has something important to lose.
I think that Liddell has a very good shot at winning this fight. I don't see Ortiz getting a KO and I don't see him wrestling Liddell down either.