Miiverse has evolved a fair bit since its launch with the Wii U in November 2012. It may not feel that way, but the network was certainly more restricted and less intuitive than its current day version, not to mention the fact that it's now available on any web browser. It's also a service that Nintendo has been able to update frequently and with ease, without any downloads or updates required of gamers.
The company has made another minor upgrade to the Wii U version of the platform in the past day, allowing you to search by nicknames rather than just by Nintendo Network ID. In theory this should make finding other users without the precise details a lot easier; here's what the never-smiling Mii for Nintendo's Marty has said in the EU version of the network.
Up until now, you could only search for other users by Nintendo Network ID, but now you can also search by nickname. To use this function, go to User Menu ⇒ Search Users.
Please be aware that, although Nintendo Network IDs are unique, nicknames are not, so you may get multiple results when performing a search by nickname.
So there you go, nothing earth-shattering but, nevertheless, welcome.