If the printers are also networked instead of wired into local clients, it is possible that network changes could be affecting print speed, but this is a really tough call to make without being inside the loop about what changes are actually being made to the network.
That fact that multiple users are reporting the issue suggests that those users, if they are all on a specifc part of the network, may have been affected by a network change to that node/branch of the network.
Have any network printers been added, removed, or relocated on the network?
I just heard from another person in IS that they are in the process of changing the IP's of the printers, and I believe changing printer names also, Because the users print to different printers based on the function they are peforming (might be creating a label, then printing a report), we hard coded the printer settings into our print scripts.
I think we've found the problem...
Thank you for your help!