There's a short item in today's Sunday Times that suggests that the
government is favouring the Heathrow Hub option:
http://www.heathrowhub.com

This is cheaper than the third runway, needs much less land (and very few
properties will be affected), will be much quicker to build, and will not
increase the noise footprint nearly as much. The scheme as proposed (not by
HAL) also includes a road-rail interchange on the M4 and GWML (and possibly
an HS2 spur), immediately to the north of the airport, with a direct light
rail link to the terminals. However, I think that's really a separate idea.

Crucially, BA is backing this scheme, rather than the third runway:
http://news.sky.com/story/ba-owner-s...cheme-10319759