Over at the Beyond3D Forums, a sharp-eyed member by the name of AnarchX posted a link to a profile on the Linked In network belonging to a hardware engineer at Nvidia.

According to his profile, the engineer has "Created package/board design guides and decap solutions for BR04, G84P, and G96" and is "currently responsible for GT214."  In addition, he has done loadline analysis and core power transient simulations for G96 and G214.  More interestingly, however, his profile states that he has also done framebuffer simulations with GDDR2, GDDR3, and GDDR5 for G96 and GT214 chips.

Although Nvidia has made no official announcement, it is important to keep in mind that the Linked In profile states the framebuffer tests were "simulations." Therefore, the idea of Nvidia implementing GDDR5 in GT214 still remains an inconclusive yet optimistic possibility.  All in all, it seems more likely that Nvidia has been closely evaluating the timing and pricing of GDDR5 and was considering whether G96 or GT214 would be the chip to introduce it.

It is simply logical that Nvidia should go GDDR5 way, sooner or later.