No release date yet but Tamiya has a new M551 Sheridan (Vietnam war version) planned for release. If the kit and figures are as good as the Archer then this will be a cool kit!
Coverage from about 7 minutes in;
RMF are also releasing one and their kits are generally pretty good too. Should give the tamiya kti a run for it's money. It does however represent a later version I think, I'm by no means an expert on the Sheridan.
M551 Sheridan !! - Went straight to the top of my 'want list' when it was announced a few weeks ago - seeing the various video reports from the show has not changed my mind one bit !! (stalking a couple of 'late version' Academy Sheridans on eBay just now aswell).