The site where "game developers speak out" Inner Bits has posted a handful of new SIXAXIS based news chunks, writing that "prototypes of the new rumble-enabled controllers have made their way to various Sony developers." Inner Bits expects that the new vibrating controllers will probably be announced within the next two or three months—on or around the dates of Games Convention and Tokyo Game Show—once developers have more hands-on time with the device.
Furthermore, it appears that the original rumble-free SIXAXIS is also getting some updates. Addressing controller sensitivity issues, Inner Bits reports that Sony has been "quietly replacing the original controllers" with better tuned hardware.
Ah, the curse of early adoption. At least we OG PLAYSTATION 3 owners have our Emotion Engines to cuddle up with late at night.
PS3 Controller News and Rumours [Inner Bits]