Never got an e-mail, but got the mailing (plus pin) today. I was very tempted to go. Would have to go down the night before because even with an early flight, I would never make it to the AGM for a 9am start.
Eurostar is £60 for a Thursday am train, back Friday pm. Val D'Europe hotel is £50 for one night according to Expedia. Add on a one day park ticket for Thurs (in the past they've given AGM attendees a free pass for the Friday) plus the cost of trains to and from London, makes the total about £165, so it all mounts up quickly.
And anyway, I don't think work would let me off for two days at such short notice.