Their press said that twin ops is safe and the trend and the 777 will be the backbone of their long haul operations. I think they are starting the PR on this front and get the customer's confidence on ETOPS (Extended Twin OPerationS or Engines Turn Or Passengers Swim).
My guess is once they prove the 777 ETOPS, they will start deploying them on TransPac. It could be messy with pricing mixing 777s with 747s on the same routes but they have to deploy 777s on LAX quickly to be competitive.
I can also see increasing frequencies - even new routes. I wonder about routes like TPE-ONT, SJC, JFK, YYZ, DFW, ATL, ORD, BWI/IAD. Also might make EWR/JFK non-stop and split SEA service.
My guess is the old 747s will be either sold or converted to cargo - not upgraded to new cabins. The very first 747 they have is over 12 years old. The Taiwanese consumer are really sensitive to old planes.
As far as EVA vs. China Airlines, I think EVA is a much less progressive company. Some examples: Evergreen Club came out really late and is not a good program, no male flight attendants, no major service improvements the last few years other than Evergreen Laurel Class.
I think they feel they can afford to be less innovative because of their safety record (or should I say CI's safety record). It is also a very top-down company and it had to get its numbers good for the IPO. IMHO, this explains why they have fallen behind on the service front.
Isn't it fun playing fantasy airline games
