Except the official name is Audition CS5.5.
...which gives you a good idea of the direction it's going. Audiition CS5.5 is being marketed specifically as an audio post production for video tool--the announcement makes no mention at all of its abilities as a stand-along audio production or editing tool.
Read the details here: http://www.adobe.com/products/audition.html
Beyond that, follow the link to the FAQ for some details of the rationale for the new product and a list of new features.
There's also a page to register for them to tell you when a download trial is available. I guess that's all we can do: download and try it to see if the "new direction" still gives us a worthwhile audio tool...or start the painful decision process about what to buy instead.
Bob