Kindle 2 Review has the list, which includes a book I've been thinking of buying -- When Genius Fails. I'm now considering not purchasing this book in protest of the crippling of this feature.
Readers have started to tag books on Amazon that have disabled TTS. These tags include no-tts and text-to-speech disabled.
I've used TTS on my Kindle on a number of occasions and have found it to be incredibly useful and that it adds to the utility of having a book in electronic format.
Are others bothered by this disabling or is it just me?