It literally takes a little over a second to currently analyze the files in a list:
Press Ctrl+A to select all the files
Right Click the files
Click Analyze Audio (Go to Options > Tree & View > Advanced and set "Right click recent command count" to 8 )
Click Analyze
You could add a Send To button on the Toolbar and possibly setup a Send To that analyzes the audio using the
Media Center Core Commands.
You can also use the following:
Ctrl+A to select all the files
Windows Key + R to bring up the Run command
Enter mc24.exe /mcc 23005 the first time and press Enter. After that it will be pre-filled unless you use Run for other stuff.
Click Analyze (or press Enter if the button is already selected)