MacRumors.com

Upon the release on the Penryn-based Mac Pros in January, Apple introduced the NVIDIA GeForce 8800GT as a new video card option. Existing Mac Pro owners initially saw this is an opportunity to upgrade from current cards as well as ailing 1900XT cards. Apple, however, quickly clarified that the new NVIDIA 8800GT was only compatible with the new Penryn Mac Pros due to firmware issues. This left older Mac Pro owners without an upgrade option.

A January statement by NVIDIA suggested a fix was imminent...

the company is "in the middle of bringing out an upgrade kit based on the NVIDIA GeForce 8800 GT solution for all Intel-based Mac Pros." What's more, this upgrade kit "should be out in a few weeks."

... but three months later, there's been no news of the upgrade option.

A recent email response from Steve Jobs suggests that the upgrade is still coming, possibly in the next month:

nVidia didn't come through, so we're having to do it. Should be ready in about a month.

Steve

Steve Jobs has been known to occasionally respond to emails, the most prominent example being an email in which he revealed calendar editing functionality that later came to the iPod touch.