http://www.dft.gov.uk/press/speechesstatements/statements/adonis20100311The announcement has this to say about the route:
"Subject to this consultation, the London terminus for the high speed line
would be Euston; the Birmingham City Centre station would be at Curzon
Street; and there would be interchange stations with Crossrail west of
Paddington and near Birmingham Airport.
HS2▸ Ltd's recommended line of route
between London and Birmingham is also published today; the Government
endorses this route, subject to further work which I have commissioned on
mitigation, and to subsequent public consultation. HS2 Ltd's recommended
route would pass in tunnel from Euston to the Crossrail Interchange west of
Paddington. It would leave London via the Ruislip area, making use of an
existing rail corridor. It would then pass by Amersham in tunnel towards
Aylesbury, before following the route of the A413 past Wendover.
"North of the Chilterns, the recommended route would follow in part the
disused Great Central rail alignment before passing Brackley and entering
Warwickshire. It would then skirt to the east of Birmingham, to enter the
city via a short link, alongside an existing rail line, beginning in the
Water Orton area, with the main line extending north to the West Coast Main
Line near Lichfield."
and Heathrow/Crossrail etc:
"It is important that Heathrow is connected to any high speed line. A prime
purpose of the proposed Crossrail Interchange is to provide such a
connection, via an 11 minute direct service to Heathrow. However, the
overwhelming majority of passengers on a high speed line south of Birmingham
would be going to or from London. This is the other reason why the Crossrail
Interchange station is so important. Crossrail, a very high capacity line,
will provide fast services direct to the West End, the City and Docklands,
catering for an estimated one third of all the passengers travelling on the
high speed line. Without this Interchange to Crossrail, congestion on the
tube from Euston would be exacerbated, and passengers would be severely
disadvantaged in getting in and through central London.
"The question is whether there is a case for an additional station at the
site of Heathrow itself. HS2 Ltd, after thorough analysis, advise that the
business case for such an additional station appears weak, given the
estimated cost of at least ^2 billion for the additional tunnelling required
to serve the site. Furthermore, Heathrow is not a single place; it is an
airport with three widely dispersed terminal centres.
"However, I am conscious that, as foreshadowed in the Government's January
2009 decision on adding capacity at Heathrow, there may be a strategic case
for a high speed station at Heathrow, particularly in the light of that
planned expansion. I have therefore appointed Lord Mawhinney, a former
Transport Secretary, to advise on the best way forward, having fully engaged
with all interested parties. A complex decision of this nature should not
be taken in a knee-jerk fashion, but after a full analysis of the facts and
options."
Paul