Any chance there is a way to change a users availability status with some Powershell-able method; command line, COM component, .Net method, Powershell cmdlet, web service, smoke signals, etc? I have searched the documentation and inin.com, and had only found a few posts asking for more command line options. Though I would love to have more scripting options, the status is the main feature I am after.

The IceLib Developer SDK comes with several example applications, one of which is a set of Powershell Cmdlets that expose some IceLib functionality. You can use the cmdlets for creating and destroying IceLib sessions, and combine that with a custom written cmdlet (following the pattern of the others) to change a user's status. This would be your best bet for automating the process.