It would be convenient to be able to select multiple meshes and rename them all.
For instance, for a chandelier, I might have 16 polymesh pieces (the arms of the model). I need to be able to select more than one at a time to rename those pieces all at once (8 upper arms, 8 lower arms, etc)
I've actually built a fairly simple script that does just this. You can find it at
https://sourceforge.net/p/aoi/discussion/228117/thread/99525aba/#3461
It's not been added to the script repository so far - I consider it working beta. If there is anything that you need this script to do that it currently does not, please reply in that thread.