You should be excited about Miiverse launching on 3DS last night. Miiverse is the most underrated feature of Wii U, one that's largely overlooked because it’s been locked into a system few people have.
But now Miiverse is on 3DS, thanks to a system update that went live for the handheld last night.
Nintendo has also introduced Nintendo Network ID onto 3DS, which means your 3DS and Wii U are now linked in a few ways. Friends lists are still sadly separate, but money lives across both platforms. Nintendo now requires a Nintendo Network ID to download from the eShop, too.
Not sure why you should begin browsing Miiverse immediately? Let me present a few examples from the brilliant Twitter account @BadMiiversePosts.