Paul Corfield wrote:

I haven't attempted to work out the numbers but there will be a
considerable increase in OSIs and their complexity come 2/1/10. As an
example just think about Waterloo NR, Waterloo W&C, Waterloo LUL,
Waterloo East and Southwark. Potentially all one complex! - whether it
ends up as one I can't say.

Conveniently, a list of OSIs from 2nd January has now appeared on "The
Manual"[1] and there are just under 200 pairs given.

Note that each gateline at a given station appears to be listed
separately, with interchange times varying from 15 minutes (e.g. Bow
Church to Bow Road) to 40 minutes (e.g. Monument to Fenchurch Street).

Cheers,

Barry

[1] An internal railway site