Those who bought a Kindle 2 on pre-order will benefit slightly from Amazon's expedience after they shipped the devices one day earlier than initially planned. The Kindle 2 was just made official earlier this month, keeping the original e-book reader's price but adding considerable amounts of feature richness.
The next challenge for Amazon is proving to the world that the Kindle concept in general is one worth adopting. While they like to say the original beat their expectations in terms of sales, it's still by far a niche device. Aside from the tactile feel of a Kindle not matching a book, one of the big setbacks for the device is its high cost. You may be able to get books cheaper for it, but at $360 upfront it looks a lot less attractive.