That is in fact incorrect. Consumer desktop Sandy Bridge, Ivy Bridge and Haswell all support 32 GB of RAM via 2 DDR3 channels. Enthusiast desktop processors (Sandy-E, Ivy-E, Haswell-E) support 64 GB, because they feature 4 channel memory controllers.
Once the consumer chipsets move up to DDR4, you will have support for 64 GB of RAM on the desktop. http://en.wikipedia.org/wiki/Skylake_%28microarchitecture%29