Minchan Kim sent in this morning another kernel patch-set for zram/zsmalloc promotion. The proposal is to move zRAM from the Linux kernel's driver/staging area to driver/blocks. The reasoning to move zRAM out of staging is that it's been there for "a LONG LONG time", it's considered stable, and zRAM is now getting lots of production use.
Minchan notes that major TV companies have been using zRAM for their compressed swap over the past two years, Android smart-phones are beginning to use zRAM for their swap, CyanogenMod is using zRAM, and Google is enabling zRAM for ChromeOS. Some lightweight-focused Linux distributions like Lubuntu are also beginning to turn on zRAM for either their swap support or as a block device for tmpfs.
Aside from systems with limited memory capacities, zRAM is also sought after for avoiding writes to disks (particularly SSDs) and providing a better interactive experience. More benefits of zRAM as trumpeted by its developers can be found by this kernel patch.
Promoting zRAM could happen for the Linux 3.12 kernel if other kernel developers agree.