I think connecting Nakuru and Eldoret - our two brand new cities make sense - even transporting maize to Nairobi is big business. With Uganda pulling out or growing cold feet - we need to lock at our national strategy - and for me - we have to terminate at Kisumu - and then try to get to Nakuru & Kisumu. Malaba doesn't make any sense unless we want to make it cheaper for ugandas - let them come for their cargo in Eldoret or Kisumu.
There is scope to of course work on old railway line with uganda - just modernize the MGR - and that will suffer transit cargo.
Anyway we need lots of railways - just look at South Africa.