There is nothing wrong with that, of course! I have recommended mindstorms as a xmas present just a few days ago, but if you are really looking at teaching programming, then you will have to work a little extra to make the kids focus on the programming part.
Squeak is quite similar to the mindstorms programming environment, all graphical, and the kids will have a blast.
So, buy the kids Lego Mindstorms for christmas and use Squeak for teaching programming...
Using squeak, you get acquainted with all the basic concepts of programming, so I believe it is a terrific starting point. Both my son and a friend of his are now ready for the next level, writing programs, and we just have to find what would be the suitable continuation (no pun intended!)
I don't want to achieve immortality through my work. I want to achieve immortality through not dying. -- Woody Allen