We're seeing a very interesting explosion of capable and affordable after market alternatives to the genuine article. Yonguo, phottix, oloong, and triopo come to mind, all in fierce competition with each other -- all are playing leap frog as regards feature sets. Phottix is combining Nikon and Canon capabilities in one unit, I presume to cut mfg cost. The more Canon-oriented Yonguo just announced an on-board radio receiver/trigger in their very affordable (560 iii) manual gun. Oloong is said to be producing a full-featured flagship clone this year, and triopo just announced another HSS gun competing directly with Yonguo's newest 568 HSS capable gun.
With the chinese guns, speedliters can affordably fill an apollo orb or a parabolic umbrealla, for example, with three or even six ETTL/HSS guns without breaking the bank. Yonguo in particular has an aparently large market share and reasonable reputation for acceptable reliability, from what I can tell. Their "flagship" HSS/ETTL capable gun is presently $170.
Yonguo appears to be the chinese gun of choice for canon users, or at least they are the emerging darling. with such fierce competition it wouldn't surprise me if they produce a 568 mark ii soon, by adding the radio recever of their model 560 iii. Its an interesting show to watch, with HSS, ETTL, and integrated radio trigger capabilities appearing in the after market. And with Canon themselves asserting true radio control with their new flagship system, the days of Pocket Wizards or other expensive radio ad-ons (for speedlites), appear to be numbered.
Frankly I'm tempted not to invest any further in the Canon guns, but just keep my 580ex ii and invest in a bunch of Yonguo guns and tranceivers. The capability you get per dollar is astonishing, and the affordable reduncancy mitigates the reliability risk. Sadly I expect Canon's next move will be some sort of digital key authorization mechanism to lock down the hot-shoe ETTL and HSS communications, preventing the chinese from reverse-engineering their stuff and selling at 1/4 the cost.