I've had the Kindle 2 since the day they were first released, and I'll never go back for travel. The eInk technology is as relaxing on the eyes as a book, and when I have tired eyes, the scalable font really helps (also good for those who have glasses/contacts who would like to read without them at times).
How much do I love it? I just purchased a netbook to travel with and will NOT be adding the Kindle for PC software to it. Nor have I added it to my Blackberry. There's just no comparison. I spend too much time staring at LCDs. When I'm reading, I want to enjoy.
I do still borrow books from the library, mostly popular fiction, to save a bit. But I resent the weight of hardbounds now, and feel less resistance to buying a popular fiction which would be a particularly good travel read. Amazon is brilliant with the Kindle and the pricing.