The .270 will be around long after the WSM, SAUM, etc have run their course. It is a classic American Cartridge capable of taking anything walking on the NA continent, with maybe the exception of the big bears where it would be considered marginal. With the advent of new bullet technology and chemistry of modern powders, I doubt we've seen the full potential of it or many other cartridges.
I've never been a big fan of it but growing up with a dad that loved every 30'06 he could afford to buy, I was somewhat disadvantaged there. Same went for the .308. To this day, I have very little use for the .270 as I'd rather shoot the 30'06 or .280 over it. Really if I'm stepping up from my 7mm08, it goes to the 7mmRM. Personally, I'm more into the SA cartridges these days, less powder, more efficient cases, less recoil and pretty comparable ballistics on any ranges that I find myself hunting.
I think it is fantastic that we have so much to choose from and it gets better every year. However, some things will never die like about any popular modern cartridge based on the venable old standard cases like the .308 and 30'06. Tried and true with so much working data to go off of means they'll be around for a long long time.