Although there hasn't been anything fundamentally wrong with the various Install.cmd/Update.cmd/CheckVersion.vbs scripts that I've been using for software repackaging in the past, I wanted to combine them into one script that run with just different command-line options to accomplish the task. I also wanted to change over from batch/VBScript to PowerShell because there were some things that PowerShell did much easier (such as event logging, accessing the registry and file properties, etc.).
At this point, the script is in a v0.5 state - it is functional, but not quite feature complete. I've tested it with repackaging the JRE and Adobe Flash players and it seems to work just fine. I've used SCCM and MDT to deploy these scripts and those work correctly, even getting the proper return codes back to facilitate reboots and other events. Using the added logging to troubleshoot what went wrong is also helpful.
Give the script description a gander here and I'll work on posting a cleaned up version of the script as a downloadable item.