This isn't actually the first time an ereader has been on TV before. I didn't log the details, but I do recall that the Kindle has been used as set decoration on the show The Big Bang Theory. It belongs to one of the characters,and while I've never seen him use it I know it has been mentioned at least twice.
Speaking of product placements, my favorite one was on the show Stargate SG1. One of the props used by the SG1 team was a rather odd looking PDA type hand held device. The prop showed up in early 2004 and was used occasionally until the end of the show in 2007.
The prop actually was a PDA that was on the market from 2003 to 2005. It was called the Tapwave Zodiac, and ran Palm OS5. It had a 4" screen, 2 SD card slots, a graphics chip (rare back then) and in general had a decent design for its day. It was a gaming PDA. (Can you believe it?)
It was really more of an inside joke than a product placement, though. I'm sure they used it because it looked unusual. Also, Tapwave didn't have the funds to buy their way into the show, and then the company folded in 2005.
But it was still fun to see it on the show (I had one at the time).