Jeff Bezos has clearly been taking lessons at the Steve Jobs School of Media Management
What Amazon did was leak news about the Kindle Fire that was almost as good as what they were about to announce. So, MG Siegler at Techcrunch got to play a little with the device and float a price point of $250. Then the name came out, the Kindle Fire. The next bit of news came from GDGT's Ryan Block who quoted a source saying the tablet hardware was based on the flailing RIM Playbook (and "pretty poor").
All of this information (aside from the value judgment) was roughly accurate, but slightly worse than the reality of Amazon's products. These reports helped calibrate people's (particularly bloggers') expectations a bit below what Amazon would actually announced. The Fire came out at $199 and its OS and web browsing have been an early hit. People are surprised by the speed of the machine and its promised "cloud-enhanced browsing." Crucially, too, Amazon held a very big punch -- the $79 Kindle -- even though they could easily have thrown it.