So I totally missed this, until I perused Baseball America's transactions.
The Astros signed 37-year old pitcher Brendan Donnelly. And they also released Clay Hensley and 1B Eric Taylor.
Donnelly, you may remember, was with the Angels in the 2002 season in which they won the World Series and was an All-Star in 2003. And with the exception of 2008, he posted a sub-4.00 ERA in each season since, though he has only thrown 34.1IP at the Major League level since 2006. And he's already 1-0 with 7H/3ER, 3.86ERA / 1.29 WHIP, 7K:2BB in 7IP.
Hensley posted the following line this season at Round Rock:
10IP, 12H/8ER, 7.20ERA / 1.90WHIP, 5K:7BB.
Taylor, 23, was 5x27 at Lancaster this season for a .185/.333/.222 line in nine games for the JetHawks.