One way of getting up to 4 years guaranteed (and it probably will last past that) is to buy an extended warranty...
, but on the high end, 4yrs including accidental handling will cost you about $100. I spent $45 for 2yrs of accidental handling coverage.
But while I want to use my Reader "forever", and hope to be able to keep it as a fondly remembered keepsake (like my old HP calculators), I expect that I'll be able to buy something even better as the technology continues to improve. Surely, in 10-20 yrs, we'll surely have a better ebook reader and for less than $100.