Actually, this is how I taught my son to ride with one of these skuut bikes:

http://www.twowheelingtots.com/skuut/

You should see my three-year-old on his coaster bike. I can no longer keep up with him, even running. I haven't transitioned him to pedals yet, but I have to feel there's something to the idea that the balance is the hard part and once you're confident in that you can pedal while you do it.

Edit: He became proficient with it slightly after his second birthday. He walked fairly late, too, after 16 months or so. I don't think he could have learned to pedal this early, but he's got the balance, steering, and speed control (braking and accelerating as needed) out of the way. Even knows how to ring a bell when passing people on jogging trails.

I got my niece a tiny one for Christmas. She's one. She loves it! As soon as her feet can touch the ground astride it, she'll be unstoppable!

What's so terrible about it?

I taught my kids this way at ages 5 and 6. It worked very well.