In that article and others I have pointed out why grid-tie systems don't make a lot of sense. For those of you who thought I was off base, Natural News has an article which comes to the same conclusion.
Because of the very fact that these systems are tied into the power grid, however, they all have a safety feature that disconnects them from the grid when the grid goes down. In other words, if the power grid goes offline, your entire grid-tie solar array becomes instantly useless and you can't power a laptop computer even if you have $100,000 worth of solar panels sitting on your roof. In a grid-tie system, they all are instantly shut off.
My grid assisted idea addresses this issue (and more).