I've only seen one ebook reader in the wild other than mine and my mom's. It was a Kindle that I saw a month or two ago at the lab in the clinic where my parents' doctors practice. I didn't get close enough to see which model it was.
On the flip side though, we've had home health care providers visiting my dad for the last few weeks, and several of them have been very interested in my K3. I even passed the MobileRead address on to one of them.