Forgot to update: Took mine in in November to get put on the list. New dash was installed in late April (Herrin-Gear Lexus, Jackson, MS). The service writer said availability, at this point, "looked to be tied to the color of the dash." She said the vast majority of the dashes they had received were black (like mine and a friend of mine, who also received his.)
On a related note, I was really concerned about the possible after-effects of having the whole dash replaced (squeaks, rattles, getting the interior dirty, etc.) However, I was pleasantly surprised that it was done perfectly and nothing rattled or squeaked on a recent 1,000 mile largely-offroad trip! The SR said they had already done over 100, so I'm glad I wasn't part of the first few having it done.......