The Ti marker was discovered in a leaked set of 266.44 GeForce drivers.
TechPowerUp has spotted the "Ti" marker used in a recently-retained set of leaked 266.44 GeForce drivers. The "Ti" marker is surprising given that Nvidia previously used it nearly a decade ago to differentiate GeForce 3 and GeForce 4 GPUs with programmable shaders (Ti) from the mainstream (MX) GPUs without the shaders.
Obviously present day Nvidia GPUs don't require markers like Ti and MX, as most Nvidia GPUs have nearly the same feature-set across the board. Still, the Nvidia GeForce GTX 560 Ti is written as clear as day in the driver set, an unreleased and unannounced GPU that assumingly isn't slated for notebooks. It's also highly unlikely that the listing is merely a typo.
As for specs, the GeForce GTX 560 Ti is based on the new GF114 silicon and features 384 CUDA cores, a 256-bit GDDR5 memory interface, and core clock speeds of 820 MHz. The new SKU is expected to arrive on January 25, 2011.