well that "/switch" link does work, and you CAN still access the classic my.yahoo as of right now. I'm glad you found google to be a decent substitute, but I don't need a substitute yet. I'll use the real thing as long as I can.
http://cm.my.yahoo.com/switch
helpful...
try clicking on this link, which is just your homepage address with the /switch added to the end of it. It should take you to a page to change back to the classic my.yahoo homepage.
http://cm.my.yahoo.com/switch
It worked for me switching my wife's homepage back. I had to do a lot of searching and going through wrong and UNhelpful answers (like the one above) before I found this simple one.