Like many other worldwide company, Yahoo always follow trends and also special dates, such as Halloween, Valentine, etc. While Google puts a banner on their logo for this special event, Yahoo do it in other ways. They put a new audible to celebrate it.
Today i just got a valentine audible (i don't know whether it's old or new audible, but i just received it today). This audible will add my collection besides the standard audible which comes with YM! and also from hidden audible that was enabled by installing hidden audible application and also getting it from friends. You can see the screenshots below.
As far as i know, audibles are in .swf format, so if you want to have a new audible, you will have to install hidden audibles or ask your friend which has a new audible to send it to you. You won't see anything at the beginning, as it tries to load them from Yahoo! server and then after it's done, it will be saved in your computer and then you can start using it. Indonesian audible are already available for a long time along with some other audible which came from several countries around the world.