No Govt decision on R3 will be taken until at least 2015 so we are unlikely to see R3 before 2025 at the earliest.
Assuming we don't get a repeat of the 2008 credit crunch, how many slots might one expect to be sold by weaker airlines to stronger airlines between now and 2020 ? How many airlines might end up leaving Heathrow and how many destinations might be deleted from the Heathrow destination list ?