DV - agree it may not (or may be - depends how you measure it) be the best - but surely it has to be the biggest in the UK at least. And one of 2-3 biggest in world.
Gillian - think the liklihood of getting in through the ballot is normally 1 in 6. This year there will be about 10-20,000 extra ballot entrants so likly that might be to be even worst this year - maybe 1 in 7 or 8.
therefore if you really want to run it would suggest you start contacting some of the charities that you support / feel strongly about and sign up for agold bond place. You will need to show how you can raise the 1500-2000 pounds required.
Good luck - the FLM is awesome and a great one for your first marathon