Also, note that Sony intro'ed some newer/cheaper readers last week. IIRC, they are going w/ epub for a more non-DRM solution.
I've been using my Kindle more and more and still love it. I took it to Whistler/Vancouver a few weeks ago and didn't get a 3G connection, I suppose Sprint doesn't have an agreement w/ Rogers up there. No matter, I just went to Amazon and downloaded the files (on my Hackintosh) and copied them to the Kindle easily. A thing to consider for non-US Kindle users, you won't have the convenience of using the 3G connection though I rarely use it.
Per a suggestion on head-fi, I also tried the MP3 capability. I've tried my Grado 325i's straight out of the Kindle and I was VERY impressed. Sound quality is on par w/ my iPhone 3G. It's a nice option when I want to read some magazine articles or newspapers and have some background music playing, while only using one device.
As far as an Apple tablet, don't hold your breath. However, there's reports that Apple is building one of the largest data centers in the world on the East Coast, NC IIRC. No one knows why though...