My brother-in-law used to be the maintainer for the telescopes up there several years ago, and is up there right now with the firefighting crews (has been for a few days now). The mountain has been in danger several times but firefighters are there in full force (well, 150 is the number I hear). From his perspective I've been getting mixed information - a lot of the news has come in via what people up there see, and what they see isn't always what's really happening (we heard an entire Christian camp up there was completely burned down, but it's actually just fine!).
A lot of the media here is hyping up the 20+ communications towers at the top of the mountain being in danger, and just started talking about the observatory recently (running out of things to talk about after days and days of coverage, I guess). It is a critical communications point, but so far between the flame retardant, back burn (?) fires started now to prevent areas from burning in the immediate future, actual firefighters and planes/helicopters dropping water/retardant, it's looking really good. The winds have died down as well which is helping quite a bit. I'm currently in Palmdale which is a bit north, and the other day it was "snowing" ashes!
One guy close to the action on the news today downgraded the fire from "angry" to "cranky" - good to hear for all of us still riding this out.