Tony, I spend about 30 days a year on the hill (some of it shooting) so here's my recommendations:
-don't waste a lot of time shooting them "in action."
-do spend a lot of time shooting them in in areas the bring out the "winter sports feel." ie: the lodge, village, maybe riding up the chair lift together kissing and whatever their fave apres ski hangout is.
-make sure to use lot's of off camera flash. it is challenging to get the subject to pop and keep the white snow exposed correctly. here is an example of how tricky snow can be (from a shot last winter). the snow to the left is exposed nicely, 10 feet to the right it is blown. go figure.
Anyhow, I'm sure you'll knock it out of the park and I wish I could be there!
Avoid action stuff unless both you and they are capable skiers/snowboarders. We've both shot slopeside, and the action photos are best when you have someone that knows what they're doing. You will waste a lot of time waiting for the lift to circle them back around. We've done one engagement shoot at a resort, but it was during the off-season.
I'd stick to primarily top-of-lift, village, and other more stationary activity shots. Some resorts, such as Park City, have additional features such as the alpine coaster and sleigh rides that you can use to your advantage as well.
We've both done the ski-bumming thing and shot for this place. They have two years of photos online, so you can get an idea on some of the poses that are possible with snow gear if you choose to go that route: http://www.rossmillerphoto.com/
