The ubuntu.com website does not mention Debian at all. The word "Debian" only appears marginally in (really old) announcements and in some per-team pages.
Since the Ubuntu universe is based on Debian, or at least for historical reasons, I think the website should mention something about Debian. A lot of collaboration among Debian and Ubuntu teams does exist and somewhere there should be a mention that Ubuntu benefits from Debian "man power".
This report is not intended to be flameable, this is a plain request to keep track of the desire by several people involved in Debian to "give credit where (a lot of people think) credit is due".