Consider mulching the leaves with your lawn mower and leaving the shredded leaves on the lawn. They will then decompose and the lawn will benefit from the organic matter. You do not want to leave unshredded leaves on the lawn as that will smother the grass. It will probably take several passes with the lawn mower but you can process a lot of leaves that way. Here's a recent article in NY Times on mulching leaves:
http://www.nytimes.com/2013/11/25/nyregion/rake-the-leaves-some-towns-say-mow-them.html?_r=0

Definitely, if the leaf cover is heavy, you should make a point of getting the leaves off.
The trouble with doing it at this late date is the leaves have absorbed a lot of moisture---be it rain, dew or snow.
Lawn mowers is the thing to use....raise the height of the wheels so you don't cut turf...the leaves stand a better chance of being lifted up.....bag them, of course.
I say, of course, because chances are with the leaves absorbing so much moisture they will be hard to cut up....no matter how sharp the blades...they'll skip out and you'll end up going over and over and over the same leaf pile in order to get any sort of volume.
Bag the leaves, throw into your compost....no compost pile...save the leaves in the bag, throw some soil in, throw some kitchen scraps in, poke holes in the bottom to let worms in, and deposit behind a hedge for later use....next summer.
Leaf mold makes for great feeding of roses.

If you find it hard to lift with the mower, you have the rake to get it done.....but whatever, don't leave them on the lawn...they'll kill the lawn faster than anything.