Code name Cariboo River
Intel is working on a new approach for Turbo Memory, since so far it has only been available for notebooks. The new card goes under the Cariboo River codename and samples are already shipping.
Cariboo River is a PCIe x1 card and it might even be the first thing using that interface that becomes installed by default by system integrators.
Considering how small of a performance advantage you get with Turbo Memory if you have more than 1GB of system memory, it might still not be a huge hit.
The other problem is that it seems to require the use if Intel's ICH9R, which is more expensive than the plain vanilla version.
If it wasn't for the fact that Intel's Turbo MEmory modules were so expensive, they might have been more popular, but as it is, it's cheaper to buy some extra RAM.