The short magnums are certainly worth considering when you make your next purchase. There's certainly nothing magic about them, but you do get a boost of a couple hundred feet per second over a standard round. I believe it was termed "near magnum velocity from a short action rifle".

Based on what I'm seeing I'd say that the WSM line has a better chance of sticking around than the RUM line. The 270WSM and 300WSM both seem poised for long term acceptance. Ammo availability is getting better in my area, and now Federal is going to produce some premium ammo for both the 270WSM and 300WSM.

I have a Browning A-bolt in 270WSM. It's a nice gun, and I like it quite a bit. It's a little lite, harder to keep steady. That being said, my favorite go-to gun is my Sako 30-06. My advice would be to shop for the gun that fits you the best. If that one happens to be a short magnum, great. If not, stick with the best fit. In the long run that's where you'll be happiest.