If you want to ever get from Bank to Canon Street, walk above ground on the street tbh. Five mins, if that, it's just round the corner. Interesting to see how Crossrail will figure within its layout!
It's more crazy that if you interchange from Charing Cross mainline to the Bakerloo line CX platforms, you're walking underground all the way to Trafalgar Square.
Stations like Waterloo/London Bridge/Kings Cross have some mightily long walks to interchange between lines, which is to be expected in some ways, but another one is Green Park, you walk for blimmin miles to interchange there...
Sounds good though, extending the 'Other Northern Line' (or the 'Southern' line maybe
). Shame QVC's now moved out of Battersea, would have been useful back when I used to have to tube/train to Battersea Park!
It's interesting how it will be the first split of the Northern line since it's formation in the 1920's, splitting back up into it's constituent parts of the City & South London Railway and the Charing Cross, Euston & Hampstead Railway (wow they certainly knew their catchy names back then...)
For a long time there's been proposals for adding a Central/Piccadilly line interchange at Park Royal/Hangar lane as the two cross over there.
What they are also planning to do is build a new Watford station and redirect the Metropolitan line:
http://www.tfl.gov.uk/corporate/projectsandschemes/2053.aspx