Thanks for all the replies. I apologize for limiting the poll to yes/no responses, just my inexperience showing. Instead I should have set it up as:
To summarize, the general feeling among respondants seems to be "yes or probably yes, IF appropriate to the setting."
Surprisingly, no-one's mentioned the Easter egg prize in Baldur's Gate I/II for solving the bronze/silver/gold pantaloons enigma - the Big Metal Rod grenade launcher! Also, in Dragon Age the Qunari (who also have mages among them) had gunpowder/cannons, so it would be only a matter of time until hand-held firearms would be developed.
I'm hoping the designers will make the firearms magic-based to some extent or have magic versions (think of the daemonic weapons in Warhammer 40K), perhaps even with sentience. I certainly didn't mean to suggest that P:E should be a shooting fest.