I agree. We have been watching them closely. We have an entirely different approach than them though. If you're interested, there is a little sign-up form for updates at www.getremark.com. We'll be releasing more info in a few weeks.
Just from these short snippets you can see that there is a lot of documentation for GPG; and that installing and using GPG will be beyond most users.
 Importantly it is crypto, and thus it's trivially easy for users to get this stuff wrong. Small mistakes do not necessarily mean anything visible to the user. The output could look real and useful, but actually be worthless.
Just filled out the survey. Small gripe: under "benefits" it was unclear if I should consider whether each feature is currently valuable, or would be valuable if I had it.
Edit: I'd also like to second DanBC's comment about super easy encryption. Having a diagram to indicate which parts of the transmission are secure would be great, too. (For instance, visually display that the email is mainly secure during transit, but is still plainly viewable by the recipient's email server.)
Thanks for the feedback! Surveys have their limitations, of course, and after years of experience I have found that (depending on the goals) it is sometimes better to allow the respondent to "interpret" a little for themselves rather than restricting them too much. Thanks again (and I have noted your encryption comments too).