We have a lot more in store, but are trying to follow the principle of deploying early & often, therefore we are now live! We have redesigned the list creation process and list editor to be more intuitive but didn't want that to delay the initial release. This will also allow us to get started with indexing on Google and applying to advertisers who require live applications. We're having trouble getting Adsense to approve our application and hope to overcome that soon. We will start a heavier marketing effort after our next major release which will include single-sign on as well.
Check it out at https://www.listturtle.com