I keep forgetting where to find the latest and somehow never use the right search terms. So, here is the location of the Amazon EC2 API Tools which include the Powershell cmdlets
http://aws.amazon.com/developertools/351
And for completeness, the AWS toolkit is here: http://aws.amazon.com/sdkfornet/
And now for Windows is here: http://aws.amazon.com/powershell/
