Tires: All Season and Winter vs. All Weather, nokian wr tires, season tires

Question
How does the performance of all weather tires compare to all season tires and winter tires.  I am considering buying a set of Nokian WR tires for my Honda Accord.  I live in Canada so I spend 1/2 of the time on snow or ice, and the other 1/2 in other summer or raining conditions.  For obvious reasons (cost, space, hassle, etc) I would prefer to have only one set of tires.  

Also I am pretty sure I know the answer but I will ask anyway; how big of a problem is it to purchase two tires for just the front axle.  I know that the front wears out about 2 1/2 times faster than the back, but the problem is that my back tires still have alot of tread on them (about 30000km).  

Answer
Paul,

There actually is a definition for "All Season" and basically it's that the tire looks like it has some snow traction.

"All Weather" seems to be a phrase that Nokian is using to differentiate its WR's from winter and all season tires.

Purchase only 2 tires?

If you read any of my posts, you'll know that I don't think this is a good idea.  For 4X4's and AWD, it's a driveline failure waiting to happen.  For the rest, it shows a lack of attention to tire rotation.  Besides, new tires ought to go on the rear to prevent spin outs.