I have recently been informed that there's a tradition here of closing certain stores this weekend to commemorate an agglomeration of the local resurrection myth with a previous pagan seasonal festival. I know some Waterstones in London are closed and others are open, but I can't find any information on that particular one. If it's closed, we can meet outside the front door and figure out where to go from there.
I have posted a backup plan, which I think is what we're likely to be doing.
UPDATE: Backup plan is to meet at the Starbucks across the road (16 Piccadilly, London W1J 0DE, 020 7287 8311). I've been trying to ring the Waterstones and the coffee shop for a while now and waited several minute for an answer with no success, so I think it's very likely that it is closed. I've called the Starbucks and it's open. If I know you on here, mail me (paul at ciphergoth dot org) and I'll give you my mobile number.
In the grand tradition of giving almost no notice for London meetups, I bring to your attention that a meetup is planned for tomorrow (Sunday 2010-04-04), at 16:00, in the 5th View cafe on top of Waterstone's bookstore. Nearest Tube Piccadilly Circus. Yvain, taw, RichardKennaway, and myself at least hope to be there, doubtless others too!
We should try to give more notice for the next one. This is the first Sunday in April; how about the first Sunday in June for the next one, 2010-06-06? I'd prefer an earlier time and it might be worth experimenting with a different venue, but if we can fix a date we can vary other details closer to the time.