Having an option to upgrade firmware is what matters.
Only if the vendor uses the capability. As an example of how not to do it, Amazon has yet to update the $400 Kindle DX software, which was announced about 2 months before the K3. It is still only partially functional compared to the K3, and the PDF support is buggier than an anthill. Pathetic customer support on that one. Guess what - I returned the one I bought...