Apparently this is not news, but I was surprised nonetheless to hear from Motorola’s Mike Patrick last week that upstream and downstream Internet traffic is roughly in balance, and has been for a few years. Downstream throughput is still the priority by far for networks operators in the US, but that has more to do with the applications that use downstream bandwidth than overall demand.
The reason cable operators are focused first on downstream channel bonding for DOCSIS 3.0, for example, is because the ability to deliver bursts of high-level throughput is critical for applications like streaming video. Consumers will accept lag time for activities like uploading photos, but there is no tolerance for stuttering slowdowns while watching an episode of Lost online.
Of course, the more people watch Lost online (or any video) at the same time, the more overall capacity comes into play and not just bandwidth bursts enabled by channel bonding.