Yahoo Stopped Yahoo Messenger For Vista Development

I’ve reviewed the Yahoo Messenger for Vista (Beta Version). However, as announced in Yahoo Messenger Blog today (Yahoo! Messenger for Vista version is no longer available), Yahoo has discontinued the 

development of it as they prefer to focus on deliver and optimize an application program that can runs on all Windows user computers - not only for Windows Vista.
All Yahoo Messenger for Vista users can still use this application. But, Yahoo won’t provide any further updates.
Yahoo also stated that they will continue the experiment of Windows Presentation Foundation(WPF), the graphic layer that powered Windows Vista user interface.