I was having a mysterious problem with my USB inputs freezing on my mac after upgrading to Mavericks. The problem happened intermittently and would freeze all USB inputs for about 10 seconds. The rest of the computer would perform normally. After some troubleshooting I finally traced this down to the Logitech Control Center and application specific configuration for my mouse. It would freeze when switching to the application I had custom settings for, most consistently when using the cmd+tab shortcut. Removing the custom settings would no longer cause USB to stop working when switching to the application.
After some searching I was able to find a post on the Logitech forums about this issue. Other people are having the same issue and it looks like they need to update their drivers for Mavericks. I tried installing the latest version of Control Center (3.8) and the problem still exists.
As an alternative to Control Center you can use USB Overdrive which allows for application specific configuration. Or you can simply remove your application specific settings until Logitech releases a fix for Control Center.