On the IBM developerWorks site there is now also mention of this chip in an introduction article about Altivec:
The only processors currently supporting AltiVec are the G4 and G5. The G4 (including model numbers 7400 and 7410) and G4+ (7450 and 7455) processors are made by Motorola. (There are more models than just the ones listed here, but these are the most widely discussed.) The G5 chips include the IBM 970, 970FX, and 970GX; these are essentially POWER4™ cores with an AltiVec unit bolted on. So far, only PowerPC® processors have had AltiVec support, not the POWER™ line. If you want to buy "a computer with AltiVec," Apple's Mac line is your most likely option. For evaluation boards and custom designs, however, you can go with any of the many vendors who do development kits based on either the G4 or G5.
Since this article is written by an independent freelance author and not by IBM itself, we cannot assume all the content in the article is completely accurate. However, we should remember than IBM has already confirmed a new chip is coming soon. It is not clear this is the same thing as the 970GX, but we do know it is a next generation chip to arrive in 2005. IBM's VP Karl Freund states that the new chip is "pretty late in the design cycle now" and that Apple will be using it.
To make a long story short, we can be pretty sure a new chip for Apple this year is a done deal. I would expect a new generation G5 in the Power Macs soon, and hopefully these will have the 3 GHz 970GX and would be announced by early June at the latest (at WWDC). Hopefully we will see an announcement of a G5 PowerBook around that time too, possibly also sporting a 970GX, at 1.8 GHz.
The reference to the 970GX has been quietly removed from the article.