This shouldn't come as much of a ... shock, but Sony is discontinuing the Sixaxis in light of the DualShock 3's arrival, according to MTV. A Sony rep says that you can likely expect them to all be gone by summertime.
The practical upshot is that if your hands have become so atrophied from a lack of physical activity that you can no longer support the DualShock's heft, you may want to stock up on featherweight Sixaxises (Sixaxi?). Good night, sweet, almost comically light prince. And flights of angels (controllable with aftertouch) sing thee to thy rest.