Danny45, Remington has a shortened version of it Ultra Mag, calleed the Short Ultra Mag. It has been reviewed in 7mm and 30 calibers. It is a way better design then the Winchester. The Winchester case is to long, making it a tight fit in a short action, or a no fit in some short actions. Heavy bullets must also be seated a little deap in the Winchester to maintain proper OAL, while the Remington short fits in any short action that will take a .308Win, assuming there is enough meat for the barrel diameter. The Remington is also a little fatter, which seems to be relevant for accuracy, as the BR and PPC cartridges exemplify.
Remingtons just a little to late getting there gun to market. They claim to have had the RSUM in the works for a couple of years, but I do not belive it. If they have had it around for so long, and they still don't have a gun in production in the RSUM, then there production, marketing and research people must be of really low quality. After all, it is a simple matter to chamber guns for the cartridge, they are already making bolts with the proper rim diameter, reamers do not take several months to make, and they must have had a small clue that Winchester was working on a short magnum. Once again, Remington dropped the ball.