RE: 30-06 vs. 270 WSM
Here's my two cents on why I take the .30-'06:
First, I don't know a thing about .270 WSM (sounds like a nifty round, though). What I do know is that someone with a .30-'06 is going to be just fine in virtually any hunting situation that demands a big game caliber.
The big question for any caliber is if its suitable for the game and conditions. With the '06 the answer's almost always yes, and many times it's magnificently so. What seals the deal for me is that it's just hard to go wrong with a .30-'06.