We will need to change our domain. We have not done this yet. However, we did put the munchkin tracking on the new dev site(not in the live environment yet). Marketo is seeing the pages that we have visited that have the munchkin tracking , but is not pulling any data back as far as who the person is on the site (even anonyomous). Any ideas/thoughts as to why this would be? Is it because the domain for our Marketo instance is different than the domain for the Dev site?
Yes. Marketo cookies are first-party, which means they only track activity on your specified domains. If your dev site was "dev.yourcompany.com" and your real site was "www.yourcompany.com", the munchkin activity would show up fine.