NGS on the other side is more or less a gradual development. While the exact technology may be novel or unique the whole process is not as can be seen by the various competing technologies that existed and still do exist within about 1 or 2 orders of magnitude in pricing over time. And gene expression read-out especially is not that novel at all given arrays existed for some time. Sure, the single applications are cool but quite a few could be done with related technologies.
But sure, in the end its not whether one thing matters more than the another as all together make a great progress.