Theres never been a service pattern decided but the early favourite of planners was extending the Wigan-Rochdale via Victoria service to Blackburn via Burnley. Wouldnt be a circular service (with their inherent problems) but would be a horseshoe on its side.
But Wigan - Vic could be extended to Yorkshire if the Northern Hub whatsit thingy gets done as the DfT would like, so mayhaps not.