VMware has released a tool called VIMA:

“The VMware Infrastructure Management Assistant (VIMA) allows developers and administrators to run agents and scripts to manage ESX and ESXi systems (version 3.5 and later). VIMA is a virtual machine that includes prepackaged software, including the latest versions of Remote CLI, VI Perl Toolkit, VMware Tools, a logging component, and an authentication component that supports non-interactive login. You can use VIMA to perform many of the tasks commonly performed in the ESX service console.” Source.

Download it here.

Update:  VMware has removed the software from their site. Neither the information page and the download page are available anymore.

Update2: As stated by Arvey Alcabes, VIMA Product Manager at VMware in the comments, VIMA is now available at http://www.vmware.com/support/developer/vima/index.html