Until just recently, one of the only ways to use PowerShell to work with the Office 2007 Suite (Word and Excel [1] primarily) was via COM. Unfortunately, COM access can be relatively slow some times.
A new CodePlex project has just started up and is blogged on the PowerShell Team blog HERE.
Definitely looks promising.
1. Yes, one can use Excel to save a particular file as a CSV, then use the *-csv cmdlets to work with the data.
