At least they get it right this time and announce early: London 2.0 RC 4 - Monday 3rd April. Hey, if adrian_h is dropping in, that would definitely be an incentive for me to hop over to London (it's just something like 7-9 hours by train from my hometown) and join in
Now I only have to check wether I can do hotel booking and ordering up front for reasonable rates around here, but what I did see is that the cheapest tickets are 49 EUR for the full drive, so there is plenty space for the hotel costs.