After some input from a coworker and a bit more digging, I found the answer. I should have tagged this question with yum!
Running yum info java-1.6.0-openjdk
showed the version installed and the available update (edited for brevity):
yum info java-1.6.0-openjdk
Installed Packages
Name : java-1.6.0-openjdk
Version : 1.6.0.0
Release : 61.1.11.11.53.amzn1
Available Packages
Name : java-1.6.0-openjdk
Version : 1.6.0.0
Release : 62.1.11.11.90.55.amzn1
Running yum install java-1.6.0-openjdk
brought the dev system to the desired state.
java -version
java version "1.6.0_24"
OpenJDK Runtime Environment (IcedTea6 1.11.11.90) (amazon-62.1.11.11.90.55.amzn1-x86_64)
Cheers,
Michael J