If you go to Admin->Tools->Welcome Email does the link appear as clickable ?
Nope - it's not.

What's funny is, there are three other links in the email that *are* clickable. They don't appear to be so in the preview (they show up as plain text in the preview) so I had assumed that it just didn't show that in the preview. But I've registered myself twice, and the links that are laready there *are* still clickable (when I get the actualy email) but the one I've created is not.