According to RTD, both in the Doctor Who Annual 2006 and occasional references in the show, the Time Lords cannot possibly exist since the Time War. They're myths and legends, with only certain "higher species" having any inkling that such a civilization existed.
Of course, you've got not a few humans such as Sarah Jane Smith, the Brigadier, and official U.N.I.T. who not only remember The Doctor, but his references to Gallifrey as well. (For example, Sarah Jane remembers being left behind by the Fourth Doctor because humans weren't allowed.)
Does this mean that humans — "stupid apes" as the Ninth Doctor called us in a fit of pique — are in fact a "higher species"? Come with me; let's take a little drive, have a chat….