There are problems, however. Firstly, journey times aren't really that bad to and from London as it is, whereas if you want to travel from Newcastle to Liverpool, be prepared to write off a big chunk of your day. Secondly, HS2 will start at Euston not St Pancras, where the high speed link to Kent and the Channel Tunnel terminates. So, any through service from say Birmingham to Paris, wouldn't stop there. Very strange concept and perhaps more to do with protecting Eurostar's market share than constructing an integrated rail system. Compare that to Berlin's Hauptbahnhof.
Personally, I think we need to improve our connections across this country outside of London, the UK is not a big country, it really should not take more than 5 hours to get from Sunderland to Bristol - a distance by road of less than 300 miles. HS2 timings and some equivalent distances are given below.
HS2 route times (current and post-HS2, from hs2.org.uk)
|Journey||Distance (miles)||Current time||Post-HS2 time||Changes|
Time ranges at morning peak for equivalent distances (from thetrainline.com)