AT&T told me December, back in November.
Comcast told me March, back in January. Then they told me April/May, back in February. I'm not sure I believe any of their "two months out" estimates. I suspect those dates are pulled out of thin air to placate the customer.
It's easier for me. Since I'm not a Comcast customer [yet], they don't get any of my money until they provide something I want to buy. I feel bad for those that are already spending the money, and living without what was promised. They'll come through at some point, though, and the frustration will fade. That's what Comcast is counting on, at least.