It’s marked as “temporarily out of stock,” but Amazon is still taking orders of Kid Icarus: Uprising for $19.99. Be sure to click on the “More Buying Choices” to find it from Amazon. It’s a Cyber Monday deal (along with Star Fox 64 3D and Ocarina of Time) at Best Buy as well.
Having just spent a bit of time playing multiplayer last night, after scanning about 100 AR Cards, I can confirm this is still a good time.
See also: More Kid Icarus media