It would be really nice if that command could become more powerful, e.g. being able to create not just ESPs but also ESLs. So:

• Replace the moldy old link with a new popup allowing you to:
  • Change the extension (.esp, .esm, etc. as supported by the game)
  • Change the name (not just 'New Mod')
  • Enable or disable the ESM and ESL flags (except for .esl and .esm files, obviously)
  • Pick any masters from the current load order (not just the game master or no masters)

Probably don't need text fields/areas for author/description, since one can easily adjust that on the Mods tab later.