Currently, when you upload a gcode directly to your printer over wifi, it gives the file a random name. (I can't recall the specifics as I'm in the middle of a print.)
You can't rename it from your printer interface because it's already printing that file.
A workaround suggested by Jason was to "Export Build File to Disk" and then upload the renamed file to the printer. This method is only SLIGHTLY less steps than my current workflow.
It would be good to add just the one more step to enable us to rename the file before uploading occurs. Some files, like configuration files, I like to keep in the UI.