Are any trains coming through the new link from Finsbury Park to the South and VV. I hope to be travelling to Ely and Cambridge later this year and was wondering if I could get a through train from perhaps London Bridge or Blackfriars?
There is timetabled to be one per hour in each direction from Cambridge (not Ely) to Brighton. The majority get cancelled. A few run each day. See here for some data from recenttraintimes.