In terms of trains calling, according to this DfT press release:

http://nds.coi.gov.uk/clientmicrosite/Content/Detail.aspx?ClientId=202&NewsAreaId=2&ReleaseID=41 4470&SubjectId=36

"From 2017, the plan is for upwards of 140 trains per hour to flow through
Farringdon as north/south Thameslink, east/west Crossrail and London
Underground services all meet at the new station."

"This would see Farringdon surpass Clapham Junction as Britain's busiest
train station and bring passengers from outer London closer to the City and
Canary Wharf."

Oh good. No doubt all the interchange flows have been properly modelled and
there'll be no problems with space on those cramped Thameslink and LU
platforms.

Paul S