I say go for it. I think this can only bring in more people to EN Publishing. Yes, while some people who play PF and know EN are probably converting already, most probably are not and others do not even bother to look more into Wotbs because it's not already "pathfinderized."
You have the material there and lots of feedback. It can't be too much to convert it, right? 3.5 isn't SO far off from Pathfinder.
PLUS, Pathfinder currently does not have any full 1-20 level campaigns and I think players really would like to see something like that. If you guys can jump on that soon, I think you'll bring in a lot of new customers.