.... about HS2, the initial line only goes to Birmingham in middle of the next decade .... let alone the extension to Manchester!
Earlier this year the Commons Transport Select Committee held an Inquiry into Phase 1 of HS2; BAA were interviewed and BAA asked whether they were satisfied with the LHR HS2 link being included in Phase 2 - and BAA replied YES; so there is no point now moaning about the late connection.
Personally I was (and still am) a supporter of the Arup Heathrow hub proposal for an interchange / terminal on the GWR between Iver & West Drayton. Interestingly Heathrow hub Ltd are one of the parties in the HS2 judicial review due to take place before Xmas.
With a further HS2 Phase 3 extension past Manchester, Leeds & Newcastle now being considered by the new Transport Secretary, it is possible (Glasgow / Edinburugh) by HST will take under 3 hours.
In terms of train substitution it is thought HSR (HS1+HS2) could eventually take between 10% and 20% of LHR's existing atms to UK and near EU airports.