Landing page URLs are now completely customizable for Enterprise Edition accounts. They will all begin with the vanity subdomain that you specified for your account but you can completely control the second part of them.
When creating or editing a landing page you can choose an optional Vanity URL that will replace the normally auto-generated address.
The following would all be valid URLs for a landing page:
If you attempt to use a URL that is already in use you will be prompted to choose a new one. Also, if you change the URL at any point, you previous URL will no longer be valid.
I have attached two screenshots for ideas.
We generally make most of our functionality available for Professional Edition accounts but this one, along with a few others in the future, are reserved for our Enterprise Edition.