Play.com has Seasons Six and Seven of M*A*S*H listed at their website to be released barely a month apart in Region 2.
According to the website, Season Six has a release date of March 28th, 2005, while Season Seven has a release date of April 25th, 2005.
Should these dates be correct, Region 2 will be caught up with Region 1 by April, as the Season Eight DVD set has a release date of June 7th in Region 1.
Source: Play.com