As a local, I can tell you Pye Corner station is around 250 yds north of the former Bassaleg Junction station.
It is a single platform but Railtrack has stated the design allows for expansion. The original track remains in situ with no connection to the new line, which has been slightly realigned into the platform. A second platform could be built on the other side of the original trackbed I suppose. I can only guess that it would be able to service a possible shuttle service to Newport, though I understand that presently, due to the signalling, train reversal is not possible on the branch, other than at the terminus of course.
There may be some murmurings about it being a white elephant but I will confidently predict that it will be just as popular as other stations on the line. Passenger loading figures to Cardiff have far exceeded what was forecast, and at peak times the train is at capacity and also well used throughought the day by shoppers. However there is still a demand for a connecting or through service to Newport for onward travel to the east and north of the country.
http://imgur.com/DgclFVG