Thanks for posting this up.
It's interesting...less than an hour ago I was looking at my K2 still showing 2.5.2.
I hadn't realized this was available on the site, but decided to take a peek in case someone had finally captured the update.
I downloaded it straight to the Kindle...went to settings, clicked on Menu and the update option was still gray. I looked down..and it was already 2.5.4.
So somewhere in that 30-45 minutes of me doing other stuff it had already updated and I didn't know it...my first update that's actually come OTA in over a year of owning a K2.
I'd always had to do them manually after a few weeks of waiting.
This will still help a lot of people though