'Is it possible to have the Wii as your primary console?'
If you're under 11: Yes.
If you're over 11: No. The time will come when waggling the Wiimote will no longer be the fun novelty it once was. The time will come when you just want to pickup a pad, laze down on a futton or bed, and just play normally, without putting any physical strain on your body. The novelty wears off way to fast for it to be a dedicated console this GEN. That kinda explain why there are so many second hand units around.