I dont know the download link, but it just popped out that a new version has been released..downloaded it…
One new feature i’ve seen is a Yahoo Firefox bar 
OK…found dload link for it
http://www.softpedia.com/get/Internet/Chat/Instant-Messaging/Yahoo-Messenger.shtml
Source : Softpedia
Check out Y!tunnel n Yahell! which is a unauthorised version of yahoo msnger.u can boot bots usin these.throw bombs n manymore…
You guys are damn late. Already posted by me on 9th aug
http://www.techenclave.com/forums/yahoo-messenger-7-final-6331.html?highlight=yahoo+messenger
Closing this one.