Originally Posted by
swingaling
They're planning to do a PKX to PEK direct link, albeit not in the way you propose. It's going to be an HSR line that goes due east to Langfang and then (more or less) directly north to PEK.
I've heard mention of a link with CBD, but not seen any definitive English language sources on the topic. That said, if one's destination is in CBD, then PEK is the logical choice.
1. At the risk of beating a dead horse, the direct link is a complete waste of resources. How often do people transfer between EWR and JFK or IAD and BWI?
2. It appears that the CBD train extension is a few years off, if it happens at all, but I'm guessing it will be pretty sweet