SAA - won't be returning anytime soon, they have been in dire straits for a while and cutting European flights rather than adding them
Qantas - likely to return through Jetstar once the equipment is available
Air India - rumours of a return have been going on for a while but nothing yet.... maybe another Indian carrier will get in there first?
Malaysian - unlikely to return, especially if Air Asia X are poised
However I don't think long haul from MAN is a write off just yet, for a regional airport there is a very good network of destinations served. I think in the future however we may potentially see a change in the profile of long haul operators towards the likes of Air Asia X, Oasis Hong Kong and Jetstar rather than traditional legacy carriers returning to routes. All three of these carriers appear to be showing an interest in operating into MAN so hopefully some good news will be just around the corner.