With more and more programs basing installation on specific machine identification numbers I think it would be useful to add in some of the more common parameters used.
One of the main values I see referenced is the hard drive serial number. This can be read currently with a simple 'dir' command from the console. Another value often used is the drive letter where the program or OS is installed (C, D, etc). Occasionally I see checks on the bios data. This command line shows the values often referred to.
wmic csproduct get name, identifyingnumber, uuid
Adding these to the next release of Speccy would be very convenient and provide another level of information about the host computer