Not really surprising, given that every other major paper that has endorsed has endorsed Bush, but the
Chronicle did endorse quite a few Democrats this year (including Richard Morrison).
On the other hand, a non-Bush endorsement would probably not have much impact, aside from driving the Chronicle's subscription base into the ground. Maybe in four or eight years we can see Texas papers give something other than pseudo-enthusiastic endorsements of Republicans (really, is it the Chronicle's "pleasure" to endorse Bush, or are they just saying that?)
The Galveston County Daily News has not yet endorsed. They did endorse a lot of local races, though, mostly Democrats, but they did spring for Republican Cheryl Johnson for Galveston County tax collector.