The Wii name raised many of eyebrows when it was first unveiled, and instantly became the butt (or the other end) of plenty of jokes. People are used to it now, so we won't see that again with the Wii U. However, the name could confuse consumers, and that's the last thing Nintendo needs right now.
Which is why we believe this new rumor from yet another "anonymous source", that Nintendo may be considering renaming the Wii U.
Nintendo's supposed reasoning is the fact there is/was too much confusion with the 3DS, and the firm struggled to explain that the 3DS was a brand-new system and not another DS revision. Your average consumer could again see the Wii U as just a Wii revision, rather than a whole new console.
If this were to happen, the official debut of a new name would likely happen at E3. Although, anonymous sources will probably just spoil it ahead of time.