Would you still be looking for a plugin that does this. I have it marked as 0.91 right now on the ZeroAlpha.us servers. I have it setup to focus on kill, as opposed to a timer. I asked about it a year or so back and no one had anything, though it was mentioned that the method CoD4 uses to show names being changed requires an action to be accomplished. I figured that 99% of the name changers we get are aimbots as well, so on kill seemed appropriate.
Current features are:
Ignore Level (Anyone over X level is ignored)
Reset on Death (self explanatory, I leave it disabled as if they're going slowly and getting killed every now an then, or just namechanging only, this could take longer)
Reset on Map Change (also self explanatory. I turn this on because on my first test about 0.3 or so into it, I thought it reset on map changes on its own. Turns out it didnt)
Notify (Notify any online admins of a namechanger with current name, number of times changed and slot number)
Auto Kick/Temp/Perm (I havent tested perm yet, I'm running 12h temp on it now and it works fine. kick also works no issue, but most auto rejoin)
Logging (Log to file, this lets you see the namechangers who've been kicked).
Number of NameChanges before action (default 10, i run 5 on the zA servers).
0.92 will be to remove some debug logging thats in the coding and it is a test of permban to make sure it functions (this is the version i'd give you). 0.93 will readd the log each name change to the Namechangers.log file. It did it previously, but I removed it for some reason or another (it was on my 5am coding binge that day). 0.94 will be full debug and comments added and changing some bits and pieces to make sure it follows the methods of coding the b3 community likes. (I didnt follow them to a t while coding this...)
after that, its possible I'll add a namechanger command to let them compare the slots so you dont auto ban namechangers, but i prefer it the method i have it, so i'm probably not going to do this. As is, namechanging with a kill will report to any online admins. As is, it's caught me 15 times now on zA NY TDM

It's gotten 3 on the NY Dom server, 1 was while 5 admins sat there and watched it tell us of his name changing until kill 5 where it banned him for it. seriously simplifies the process and takes the hackers down a notch.
I dont generally visit the b3 forums too often, so feel free to pm me on zeroalpha or here and I'll get you the permban tested version.
--NRP|pyr0