Loking at hardware sales, unit wise, you might argue that there are some similarities between Wii U and the Dreamcast. However, that comparison isn't too relevant. What matters the most is the ability to make money.
Sega (and Dreamcast in particular) had major flaws when it came to making money.
1. Segas arcade division wasn't as profitable as it used to be, and their home entertainment divisions couldn't make up for lost ground elsewhere.
2. Sega had lost quite a few loyal supporters from the Megadrive era because of how the company treated its loyal supporters (the release of the Sega CD and the 32X did so much long term damage to the company).
3. The hardware in Dreamcast (as well as marketing of the system) was too expensive.
4. Dreamcast's copy protection was easily hacked. Many users were not die hard loyalists who prefered buying games. Instead piracy became a major issue that prevented the Dreamcast from making money.
5. All of the above, and the fact that Microsoft was about to enter the video game market, scared Sega into a series of defensive measures that made them abandon their hardware business.
From what I can see, Nintendo is in a much better position to make money out of the Wii U (even with its current low sales).







