There a number of PKX threads on FT now, so I'm uncertain of which ones I've posted to, but allow me to explain my view on the situation:
-CZ can easily move airplanes from CAN/WUH/URC in order to dominate PKX in a major way
-AA and BA want this because it will finally give them a way to actually serve 2nd and 3rd tier cities in China; CX/KA wants to play this role, but we all know that they don't play it very well
-BUT, CZ isn't going to seriously ramp up PKX until people get used to PKX
-we've all read about how great PKX --including ground transportation-- is, but these are still largely untested waters
-my personal prediction is that PKX (and CZ) will be a HUGE success within the course of the next 5 years
-I can't foresee CZ ever joining OW
*they are unwanted by CX (this is an understatement)
*they are the largest airline in China
*they have 40% of the slots at the (soon to be) largest airport in China
*strong partnerships AA, BA, AY, and QF
*why would they pay alliance dues when one of the founding members of the alliance despises them?
*I honestly believe that there is a good chance that CZ will be the largest airline in the world fairly soon IFF PKX catches on
*we think of them as a Guangzhou airline, and Guangzhou works fine for Europe-SE Asia and Europe-Australia. Beijing is a MUCH more value asset than Guangzhou

In closing, if people end up preferring (or at least being impartial) PKX v PEK, this ship will sail. That having been said, CZ is not going to blanket Asia with PKX flights until it gets some some data on the viability of PKX. I firmly believe that their plan (including the JVs) will work in due course, but let's not expect flights to places like Changsha until the airport itself gets traction.