...get the sun to look like that, instead of washing out half the image? Polarizer?
It's the quality of the lens. From what I understand, the sun working differently with the optics of each lens and how it's constructed. Canon L lenses are expensive but deal with direct sunlight very well. Polarizers work best at angles around 90-degrees from the sun, so with direct sunlight I've never found there to be an advantage using them.
Also, use the spot metering of your camera to detail the exact exposure to want (the snow, sky, direct sun, clouds, etc.) With some practice you'll notice when the photos are washed out or too dark. Also, bracket your photos. Pre-set the camera to take three burst of photos every time you push the shutter. Between the high, medium, or low exposure, you're bound to hit the sweet spot.
Canon L lenses, huh? Right now I'm using Olympus kit lenses, which are about as good of kit lenses as you can get, and lightweight as well, plus with Olympus the image stabilization is in the body instead of expensively duplicated in each lens like with Canon and Nikon, but I'd like eventually to get a higher quality, wider-angle lens anyway. I'm such a cheapskate. I can meter for the snow, ground, blue sky, etc., and that turns out fine but the corner of the shot where the sun is usually doesn't look as crisp; perhaps you're right, the lens may be scattering the light. Thanks for the tip.