Is anyone using an SNMP and/or WMI poller to push custom metrics to Amazon CloudWatch, and if so how?

Amazon CloudWatch has a decent console, and an alarm system which uses Amazon SNS for notifications.

Originally it only gave you AWS metrics, e.g. EC2 instance CPU utilization.

Recently they added custom metrics. You can use the CloudWatch REST API to push your own arbitrary metrics.

I'm wondering if anyone has tried to use an agent that would poll various servers (some at EC2, some not) via SNMP and/or WMI, and push those samples as custom metrics to CloudWatch? So now in CloudWatch you can see all your metrics (both AWS and not) together in one place.

Note: I understand that some monitoring tools can pull from EC2, which is another way to get everything in one place, and might be superior to some people for a variety of reasons. But I'm asking about the way where CloudWatch is the one place.

If anyone is doing this, what are you using as the agent?

This might help in one way -- http://blog.monitis.com/index.php/2012/02/27/monitis-custom-monitors-for-amazon-aws-cloudwatch-metrics/

This is perhaps what we need -- http://community.zenoss.org/docs/DOC-4423