It still works - just a little annoying and a couple extra steps to sign in each time- but if you really want it to work- it'll do.- see below
1) from home page--->menu--->settings-->applications--->manage applications--->voice and video add-on for yahoo--->uninstall
2) start messenger---->initiate video call---->you will get a messgae telling you that VIDEO SUPPORT NOT INSTALLED and asking you if you want to go to the market to install it---->hit cancel--->without closing the messenger app go to the ORIGINAL yahoo_imvideo.apk that you downloaded (I do it with Astro) and install it (DO NOT MISTAKENLY INSTALL IMVIDEO_4002.APK that's the upgrade that disables the video) .
Now when you go back to the running messenger, video call should work just fine.
As long as you keep the app running you're good to go, if you stop it you have to uninstall as above and follow the steps again -it's actually not as complicated as it appears once you've done it, especially if you remember to uninstall the video add-on as soon as you close messenger, then it's one additional step after you re-open it.
Certainy is a minor, and hopefully soon-to-be unnecessary PITA, though.
Mark