Excursionist (http://excursionist.com) - Create and book unique, one-of-a-kind travel experiences. Definitely targeted at a higher end consumer. Worth watching for the way they editorialize places.
SideTour (http://sidetour.com) - Hosts create unique experiences. Users then buy those experiences. Looks like hosts write the copy for each experience, which (if that is in fact the truth) saves a lot of time on copywriting. Once you have the infrastructure you could theoretically scale across the world.
Overall I like the idea, but as a consumer I have a few thoughts.
1. I think it's going to be really important to separate yourself from the existing competition. Otherwise I probably won't sign up for yet another newsletter when I really only take a one or two trips a year. 2. The vetting/quality control process will be extremely important. If I'm going to climb Everest with someone, I really want to make sure the experience in their profile is in fact true. 3. Finesse re: selling me at the right time will go a long way. I don't know if this means you hit me when I'm actually booking a trip or what, but unless the way you present this experiences is incredibly entertaining/awe inspiring, this context factor could very easily make the difference between pestering the consumer and offering a once-in-a-lifetime experience. I don't think UrbanDaddy Jetset or Gilt's Jetsetter has this quite figured out. Though I'm sure they still make money, figuring out a way to present yourself more effectively could go a long way.
Whatever the case, I still think there's room for innovation in the space.