The 40 and 80 Gb PS3 have a different IC CHIP which is not compatable with the current adaptors. We are waiting for a new adaptor to be made available. (I got this from Harts Unlimited).
Here is what Konami said about PS3 DDR games. I emailed them since they make many of the DDR games out:
Thank you for contacting Konami Support.
This game is not intended for play on the PLAYSTATION®3, but will function with the controllers for the PLAYSTATION®3. At this point as there are no dance games for the PS3 from our company (and no information available on when or if one will be) we do not have a mat or an adapter that will function with this system. If an adapter were to be manufactured to aid in the use of ANY non-standard peripheral on the PLAYSTATION®3, it would come via SONY.
We recommend you regularly visit our website for all up-to-date information.
BOTTOM LINE: No DDR for PS3 anytime soon.