I ready here that Nvidia has confirmed that it is working on Optimus so that it can be supported by Linux. This is great news, but what's the realistic outlook of this? When will the actual working drivers come out for Linux?

I was unlucky enough to buy a powerful mobile GPU, the GeForce GTX 675m, but my computer's BIOS doesn't have the option to disable discrete graphics so I've never been able to use my GPU, except for with Bumblebee but it kind of sucks (it makes most games slower and less stable than with the CPU). So hearing the news that I may one day be able to switch between discrete graphics and Nvidia was really relieving.

So what do you think about this? When's it suppose to be ready to use on Linux?

This is really great news since up to this point NVIDIA Optimus laptops have been a pain to use properly under Linux. While there is DMA-BUF/PRIME support for the Nouveau driver, using the reverse-engineered open-source NVIDIA driver isn't ideal there since the driver lacks reliable and useful power management support (a.k.a. a very short battery life and potentially a warm lap). Let's hope this support gets stabilized soon.