I went with a similar strategy with a site I put together, JimAsks.me ( http://www.jimasks.me ). I went as far as to create the account for the user with pseudo data, and then giving them the chance to go back and update the account data if they wish. If anyone answered a question, regardless of whether they had created an account or not, I wanted to be able to display that response and by tying it to a persona, I was able to do that. This signup process was presented in a paragraph form similar to the site discussed here (just answer a question you'll get a chance to "change your account" where you'll see my form).

I didn't see any uptick in those who signed up. But the generation of anonymous accounts on behalf of the user certainly did increase the interaction with my site.