TVShowsOnDVD.com has posted a news article giving the Season 10 DVD set a Region 1 release date of May 23rd, 2006. This is a bit earlier than the tentative June 2006 date that was included on the insert found in the Season Nine set, but given an earlier report that a complete boxed set will be released by the end of the year, it seems about right. As always, the date is subject to change without notice.
Source: TVShowsOnDVD.com