Over the summer, I slowly realized that the stability of traveling only for fun rather than weekly for work was great for my sanity. It's allowed me to settle into a city and have a more consistent and sane life than when I'd been spending 100+ nights/year in hotels for work.
After much debate, I decided to stay here in London on a more-permanent basis, rather than returning to New York in January 2010. In making this decision, I've also resigned from my firm and accepted a job with the primary client I've worked with for the past year.
Assuming my application for a new work permit goes through on the expected timetable, my last day with my current employer is going to be 23 October, and I'll be continuing on my current project as a permanent London-based employee rather than as a consultant from 26 October.