Think your list is out of date...
Air Comet - Groundstar
Atlas Blue - Servisair
Delta - Servisair
Ethiad - moved to LHR last year and before that were handled by Servisair
Afriqiyah - already gone to Groundstar
Estonian - Servisair
Ethiopian - not currently operating to LGW - just LHR
But yes, it will be interesting to see who gets what... and lets hope all the Aviance staff being made redundant get taken on by the other handling agents.