It's just a rumour at this point, so take it with a pinch of salt, but there are some suggesting that if you buy a pre-owned Nintendo Wii U console, that you can download games bought by the previous console's owner, as they remain registered to the hardware.
While it's been claimed by the poster over at NeoGaf, that the console was as-new when he received it, upon visiting the Nintendo store, he found several games had no price attached to them, allowing him to download them for free. To date, he's received Trine 2 and Nano Assault without paying anything.
Some have suggested that it may just be a case of the original console owner not quite deleting all account information before reselling it, but the OP claims it was fully wiped and that he opened a new free account before being able to download the games.
At the time of writing Nintendo hasn't commented on the rumour and if it's true, this would certainly seem like an oversight on their part. However as Kotaku points out, Nintendo isn't as well versed in the world of online sales and storage as other companies, so perhaps this flaw slipped through the cracks.
KitGuru Says: I imagine not many people have second hand Wii U consoles at this point, but it might be the way to go if you're considering buying one.