I just had a quick look down there. The mood is a bit sombre given the poor weather and most people are still at work, however each of the stands are undercover and I'm sure that everyone will crowd in later.
They have a reasonable range of beers, although I'm not sure if they have beers from 40 breweries as they have advertised. Perhaps there will be more breweries tomorrow + Sunday?
I would like to have tried Zatec (sounds like a hayfever medication) from the Czech Republic.
The only other beer that I hadn't tried was advertised on a poster (didn't see any bottles). It looked like an Aussie microbrew as it had a dog on the label (I can't remember the name of the beer).
They also have Little Creatures, Leffe, Budvar, DAB, Lucky, Erdinger, Michelob, Budweiser (I think?) + others.