Wii U constantly freezing - defective or firmware bug?

I've had a Wii U since November 18th, and up until the most recent firmware update, the system has been working fairly well, with one instance where it froze.

However, after the update, my system has been freezing up constantly, with roughly three freezes today alone. Each time, the system was trying to connect to some form of networked service, such as the Miiverse or COD multiplayer. I'm wondering if this could be a sign of a defective unit, or if it is just a harmless firmware bug?

Has anyone else been having their systems freeze up? If so, then it's likely just a firmware issue.

Seems to only happen when trying to access the internet.

I hate unplugging the power cord every time it freezes, but there doesn't seem to be any viable alternatives.