What Flightrider says is my interpertation as well.
I've not seen any intention from SAS to open new routes or markets, the London base will fly existing routes to Scandinavia. It's just the crew and aircraft will be based at Heathrow and therefore no need for night-stops and expenses for crews. Combine this with lower employment costs in "Ireland" compared to Scandianvia and that is another cost saving.
I don't think SAS has any intention of trying to make money out of leisure routes from the UK, at least not at the moment.