As of this post the answer is
YES
Automatic way to fix...
Download
Vista Voice Fix and follow onscreen instructions.
Manual Fix below...
Please note: You should run the following installers as administrator
To use Yahoo! Voice Chat in vista you must have the following.
DSP group Truspeech Codec -
Download it here!
Yahoo! Messenger 8.1.0.416 and above! (8.1.0.421 is recommended)
Download Yahoo Messenger 8.1.0.421
Once both are installed as administrator you should have voice chat access!
Also note you may be required for your mic to be inserted for initialisation
For 3rd Party Chat Clients (YahELite, Yazak, Y!mLite, etc.)
1) Exit out of the chat client(s) you're currently using completely.
Depending on if you already have the TrueSpeech codec installed or not, do one of the following:
2a) If you don't have the TrueSpeech codec installed, download
this file and save it to the desktop when it prompts.
2b) If you already have the TrueSpeech codec installed, download the
this file and save it to the desktop when it prompts.
3) Right click on the downloaded VistaVoiceFix.exe file (or the VistaVoice_dll.exe file if you already had the TrueSpeech codec installed), and select Run as Administrator and install it (follow the instructions and select Yes or Ok for everything it prompts).
4) Start up your chat client(s), go to a chat room, and attempt to gain voice chat. If you appear connected, SUCCESS!!!!