I can confirm this:
I received my Kindle 2 days ago. On a whim, I took out the 8 GB SDHC card from my Nikon Coolpix P5100 and put it in the Kindle. The Kindle read it and said there was 7.5 GB available on the card, which is about right. I'm ordering another one from Amazon to use in my Kindle. If you're interested, it's this one:
http://www.amazon.com/Transcend-8GB-...2447552&sr=8-1
I'm an Amazon Prime customer, so shipping was free... what more can you ask for?