I had my N10 replaced due to wifi issues, and although the wifi is still somewhat flaky (this is definitely a Jellybean issue), I'm satisfied with my replacement.
Here is what the replacement process is like:
1. You call Google, and place a replacement order.
2. They will send you the replacement, but a "hold" in the amount of $399.99 will be placed on your credit card until you send back your old device. (It's up to you; you can send your old N10 as soon as you hang up the phone, or you can wait until the new one arrives. I kept my old one until I received my replacement)
3. As soon as you ship your old device, the hold will be removed.
Because I had my replacement ordered last month, I got the new device in three days. I don't know how long you'd have to wait if you order now. I suggest you order one as soon as you can!