Here are simple steps to install Datadog's agent on FC17. These steps are meant to be work-arounds until we officially support Fedora Core.
If you have /etc/yum.repos.d/datadog.repo, delete that file and run sudo yum makecache
Install python-tornado from FC repositories
sudo yum install python-tornado-2.2.1-1.fc17
Install datadog-agent
sudo yum localinstall http://dd-ops.s3.amazonaws.com/datadog-agent-3.4.3-621.noarch.rpm
Edit your configuration file and add your API key
sudo vim /etc/dd-agent/datadog.conf # or emacs if you prefer
Finally restart the agent.
sudo service datadog-agent restart
The crux of the issue is that the agent requires Tornado to run and that yum is not able to solve complex constraints ("the most up-to-date package that satisfies X, Y or Z").
Older RedHat derivatives did not include recent tornado packages (if at all) so we distribute our own packaged version, python-tornado 2.3, with a dependency on python and an implicit dependency on python 2.6. FC17 ships with python 2.7 and python-tornado 2.2.1, with a dependency on python 2.7.
Thus installing our packaged version python-tornado on FC17 works but the package ends up in python 2.6 directories. It is not picked up by python 2.7, causing the agent to fail.