If you've been aggravated at your iPhone or iPod touch in the past for its inability to play back WAV voicemail files from home phone services like Vonage or AT&T (synergy foul! yellow card), you may now breathe easier. TJ Luoma was 95% through building a rather elaborate script to convert incoming WAV voicemails to MP3 for iPhone playback (and, while he was at it, add some reverse lookup magic) when he discovered that the 2.0 firmware now includes the ability to play back the particular flavor of WAV file used in these voicemails. Problem solved.
It may not be a headline feature (or even a stealthy but universally acclaimed UI addition) but for those of us who need it, it's going to save a lot of time and trouble.
Thanks to TJ & to Curt for independently sending this one in.