Yes the Fireball 3, and DiamondMax+ 8 and 9 have been shipping for a few weeks now.
However if you read the spec sheets on the 9 series Maxtor will have 8mb buffered version. As well as serial ata drives in that series. I have checked my distrubiters last week and nobody can get any of the 8mb or serial ata drives (they just arn't being shipped out from maxtor yet). Also not even the 160gb 9 series drives in 2mb buffer is avialable either.
The Western Digital drives have been shipping for over a month and are in retail stores now.
In fact I just got a fireball 3 for my sister's computer just last week.