As I said in the Ron Paul thread...Ron Paul and Gary Johnson should certainly not both run...if Johnson were to step aside, Ron Paul running would be great. If not, Gary Johnson should be the only one runnin, and he has my vote. Assuming that is the way it goes, we need to get him that 15%.
Yes, Gary Johnson and Ron Paul have very similar stances on everything except for abortion (Paul is pro-life while Johnson is pro-choice). Also, Paul is a Creationist and Johnson an Evolutionist. I'd say the fact that Paul believes in freaking Creationism gives the edge to Johnson overall.