I don't know whether it was already mentioned somewhere, I couldn't find it.
I believe this could be nice feature, I am really missing it right now.
My example - I have list of requirements with priorities I imported to TL.
Unfortunately, while importing CSV I couldn't add the priority field so I have to now put it manually. And I have to do it one by one by one... and there are loads of them and I am getting sick of it

It would be nice to have tool to upload selected field to chosen value for more than one item (requirement in this case, but could work for other things as well). Then I could select all set of reqs and choose "update field priority to Must Have value" and it will take just a moment.
Now I am already thinking about messing with DB with SQL statements, because this clicking is gonna kill me.
And unfortunately - no, I can't do this on my own. I would with pleasure, but I'm no programmer.
I know you have loads of work, but what do you think?