Lance talking about "un-retiring" has happened even faster than I had expected, I thought he would take at least one year off. Some more info from Cyclingnews.com:

Johan Bruyneel in his team car at the Vuelta a Espana and he told us that "Yes, the quote from Lance in the Austin American Statesman is certain. You know, we had some retirement parties in Nice after the Tour and then Lance went back to the States and took it easy for a few weeks. Then he called me three weeks later and said 'I'm back on the bike... I'm getting bored and missing the exercise, the riding'."

Bruyneel explained that "I'm not excluding a comeback by Lance for 2006, but can't confirm anything until I talk to him. But it's not impossible."

So it will be interesting to see what takes place over the next couple of months.