As major fantasy epics like Lord of the Rings and A Song of Ice and Fire have become incredibly popular, their science fiction equivalents haven’t. Salon speculates that that might change for Dune, given its reputation for focusing on ecology and environmental issues.
I disagree with the base assumption of this article right off. If anything it’s the other way around. Suddenly fantasy is popular in mass media while science fiction has been rolling along for decades in mass media mostly untrammeled. Given semi-picaresque serials and closely plotted stuff like Firefly and the reboot of BSG, which are roughly contemporary, you could argue that space opera is doing just fine.