Several articles on this story have pointed out "In addition, the company will continue to offer Windows XP Starter Edition in emerging markets where it is currently available for the rapidly growing class of hardware-constrained ultra-low cost PCs until June 30, 2010." So it looks like third world countries will be able to buy for an additional 2 years.

I would think this would be dificult for several reasons:

1. the fighter plane will not remain stationary in the air while it fires the laser beam

2. it's not a continuous beam

3. the people on the ground shouldn't have the accuracy that a fighter plane with targeting equipment does

In all likelyhood, reflecting the beam back is a very slim probability, most certainly until ground troops get man-mounted, extremely accurate targeting systems. Which I don't think they have now nor do I think they will have for a while. Especially since one small movement places your point of aim onto a point in space much farther from where it was before, without the stability of the plane, a human couldn't reflect that beam back very well.