Hadoop Vs. Disco Vs. Condor?
I'm unfamiliar with Disco and Condor, but I can answer regarding Hadoop:
Hadoop pros: 

Robust and proven - probably more than anything else out there. Used by many organizations (including the one I work for) to run clusters of 100s of nodes and more.
Large ecosystem = support + many subprojects to make life easier (e.g. Pig, Hive)
Python support should be possible through the streaming MR feature, or maybe Jython?

Hadoop cons:

Neither simple nor elegant (imho). You'll have to spend time learning.
I am trying to find a tool that will manage a bunch of jobs on 100 machines in a cluster (submit the jobs to the machines; make sure that jobs are run etc).
Which tool would be more simple to install / manage:
(1) Hadoop?
(2) Disco?
(3) Condor?
Ideally, I am searching for a solution that would be as simple as possible, yet be robust.
Python integration is also a plus.