As much as I hate being "that guy" who posts his anecdotal evidence, I'll post this anyway and people can take it for what it's worth:
When we were at Disneyland last week, there were never more than a handful of people queue'd up for EO. Given the guests I saw for it, I would bet it's in the bottom 10% in terms of attraction popularity there. Just a bet, though.
Like I said, take this information for what it's worth. I think at one point, EO was really popular out there, but I think that day has come and gone.
Personally, I really hope the plans for Tomorrowland at DLR that have been circulating come to fruition sooner rather than later. That land is a mess and although the kinetics improved a bit with the new Star Tours exterior, there is still a lot of work to be done.