Let me just say that I loved the DreamcastTh. The system was awesome with its great controller, the amazing VMU, and the excellent games. The Dreamcast was a very innovative system, with its controls, memory card, and internet connection. The Wii U seems to be trying similar things although the level of innovation is not quite what we had hoped for.
Unfortunately, it also looks like a system caught between generations. It is more powerful than the Wii, 360 and PS3 but not even close to the Xbox One or PS4. However, just like the Wii it has great games. Unfortunately, most of these games have to come from Nintendo since 3rd party support on the system has been very lackluster. This is fairly similar to what happened to the Dreamcast.
Shenume
Jet Set Radio
Soul Calibur
Skies of Arcadia
Those are some of the amazing games that adopters of the Dreamcast got at it was wonderful.
Super Mario Galaxy
Legend of Zelda Skyward Sword
Xenoblade Chronicles
Madworld
and more can be found on Wii U
If you are looking for a second system buy the Wii U and do not let it go the way of the Dreamcast.