AC,
After what I've read in the Belgian newspapers, SN would continue to operate the flights for a few more weeks or months, but BA would be taking over all of them afterwards.
Apparently SN wanted to make A/C available for new destinations and get access to the OneWorld alliance, and I suppose BA is trying to get VEX out of the game.
I think SN sold all their LHR slots to BA, but only a few months ago they seem to have sold some to VEX as well. Basically this would mean that SN does not have slots any longer in Heathrow.
If others on this forum have some more info would be great to know.
Cheers
CIV5C