[caminante]

  China won't be able to afford this;

It doesn't need to. FTA:

  "The Chinese government will invite private investment to participate in funding 
  intercity and regional rail lines"

This is how Europe has been doing it despite heavy public debt. In this plan, China will setup public-private partnerships to raise capital. Also, the article also mentions functional privatization efforts, a new precedent for Chinese rail, which opens the door for more investor capital:

  "Earlier this year, China turned to a private company for first time to operate an 
  inter-city rail service on the mainland"