You can move them now. I am sure some folks will tell you to wait until spring....but Hostas are incredibly tough plants. I have moved them and/or planted bare root in late October midst flying snow. Didn't phase them a bit. Came back in the spring with flying colors.

You actually lucked out with your question. There is a recent post on the Hosta forum with pictures and step-by-step instructions on how to move large hostas. Excellent info. See the link below.

If you are going to be dividing, here is another pictorial and a step-by-step 'How to' http://forums.gardenweb.com/forums/load/hosta/msg0923132429508.html?12

Make sure you keep the new transplants very well watered as late into the fall as possible.
Jan

Here is a link that might be useful: moving a large hosta

OMG, that link to which you sent me is AWESOME. I cannot thank you enough for providing me with that post. YAY. Way too cool.