The .35 Whelen is a great cartridge, in between a .30-06 and a .338WM. It would be a great cartridge for bear, elk, moose and deer. It will not have quite the trajectory of a .30-06, 7mm etc, but will be adequate.
If you already own a .270 or .30-06, it would be about the perfect cartridge to compliment that, as your second rifle.
If you're gonna own 2 rifles, I've always figured the perfect combination to own is a .270 or .30-06 along with a .35Whelen or .338WM.
The only knock against it might be that you cannot buy ammo just anywhere, but as long as you got access to Wholesale Sports, Russell Sports, P&D Enterprises etc, then you should always be able to find it. Better yet is to take up reloading and "roll your own"...