Keith's Note: If you watch the live video from the Aquarius undersea habitat you can see that the NEEMO-15 crew are currently using tablet computers. According to an interview I did a few minutes ago, NEEMO-15 crew member Astronaut Shannon Walker says that they use these tablet computers to track their mission tasks. Walker also said that there will be several tablet computers aboard the next Progress cargo flight to the International Space Station. When asked, she was not able to say what brands of tablets would be going up.
Keith's update: According to NASA Public Affairs, the Russians plan to fly two iPads on the December Progress mission as a replacement for the iPod they currently have on the ISS The only use for these two iPads will be for entertainment. The Russians have no plans to use them operationally. NASA is still reviewing other tablet systems and plans to fly at least one more next year although the brand that they will fly is still TBD.