I've been working the last few weeks on getting SDK Paint's gallery website ready for online sharing for the Wii U and for the iPad. Once it officially launches, it will be an integral part of this community, working with the same member accounts you already have. There's some sample art posted there that you can rate. You can also post comments in a similar manner to the blogs here. If you are using a Nintendo 3DS or New Nintendo 3DS, you can view the art in 3D by choosing the MPO image format.
You can actually download the iPad app now and post art to the website, but the Wii U connection won't be ready for at least a month - when SDK Paint is updated in the Nintendo eShop.
There are a few items left to-do, like sorting art by ranking, quickly advancing through art while eating, etc. The core functionality is in love, though.
If anyone is interested, can you check out the website and provide feedback? Thanks!