Sorry to dig this thread up, but attached is a sample of the proposed 6tph pattern - I stumbled across it on a Rail Users group on Facebook, but I've also seen it referenced elsewhere.
In summary:
2tph Corby calling at Luton Airport (1tph), Luton (the other tph), Bedford, Wellingborough, Kettering & Corby
1tph Nottingham - calls Kettering, Market Harborough, Leicester, East Mids Parkway & Nottingham
1tph Nottingham - calls Market Harborough, Leicester, Loughborough, Beeston & Nottingham
1tph Sheffield - Leicester, East Mids Parkway, Derby, Chesterfield & Sheffield
1tph Sheffield - Leicester, Loughborough, Long Eaton, Derby, Chesterfield & Sheffield.
It doesn't seem to have extra stops at peak times, but it's disappointing that Nottingham in 90 won't be achieved any time soon, and also that to get from, say, Loughborough to Bedford requires 2 changes.