Candace in London gave me this information:
Michelle Obama is indeed coming to London on October 15 for three fundraisers at the Landmark Hotel. Below is the link/invitation for the $2300 and $1000 events. Admission to the events will be the printout of the contribution confirmation and your passport.
Click here to sign up.
FYI: there will also be a grassroots event that same evening at $100 but that link isn't yet in place. For questions on procedure, et.al, contact Diana Clark at dianasclark(at)mac.com.