A little update.
The boxes with the pens are still on the shelves. They are disappearing though. Don't forget to check Big Lots or Dollar General too, they have cereal as well.
You'd think that the AOTC Star Wars cereal would come with those darn pens but they don't.
I've bought 4 boxes of cereal with the pen offer so far (a Honey Nut Cheerios 2 pack, Reese Puffs and 2 Cinnamon Toast Crunch) and I got 1 Dooku, 1 Windu, 1 Vader and 1 Luke. Still need an Ani.