Jabird, agree with all you said, the reason I spoke to TfL was because the DfT are not remotely interested in talking - especialy when there's any remote reference to the third runway at LHR. More importantly, one person at the DfT - Theresa Villiers, appears to be incredibly negative and or disinterested about aviation - period. How she can do her job effectively with this view astounds me, and I'm sure it is not helping the aviation industry in the UK as we see the need for modernisation , growth and properly integrated intermodal transport.
The cost of the recommendations would be dependent on a lot of issues, and you are right, it would need a Parliamentary decision. My hope was that using the TfL report on a new airport for London issued earlier this year could pave the way for talks with the relevant people. Sadly that looks unlikely at the moment.
The 2003 white paper interestingly dismissed a few growth alternatives because it was a foregone conclusion pretty much that the 3rd rwy would be built, and T5 was going to be complete.
I agree about the new thread...
Lastly - this is quite relevant:
Chinese carriers slash fares, improve service to compete with high-speed rail | ATWOnline