With the advent of quad-core ARM CPUs, the RAM requirement of smartphones are heading towards territories previously occupied by desktop PCs.
For that reason, Samsung has just announced that they are mass producing 20nm 4GB LPDDR2 Mobile DRAM, with a throughput of 1066 Mbps
http://en.akihabaranews.com/112371/storage/samsung-initiates-world%E2%80%99s-first-mass-production-of-20-nano-class-4gb-lpddr2-mobile-memory
If you can wait, upgrade your smartphones next year