I'll have to admit the only reason I listen to 103.9 during the morning Talk is because of Kelly Quinn. I've been listening to her since she was on 92.3 back in the 80s, so it's like listening to a friend from back when I was in high school (even though a graduated years earlier).
Although I think 103.9 would do better as a music format, I doubt they will get rid of their talk format.... at least not yet. However, if any station were to flip formats, I think stunting as a 24x7 Polka station would really catch peoples attention.
As for the 80s format, I wouldn't say it is stale, just that Radio stations are playing the same 80s hits over and over again. When all you play is the same 100 songs from a decade, its going to sound very stale. If an 80s station were to make it today, I think they would have to play a wide variety of songs from the 80s, not just the one that the Mix and the Brew play. Of course 107.9 having been America's 1st 80s Station, they could easily put 80s on their HD channel as they phase it out of the Mix. But as I just said, they would have to have a wide variety of 80s songs.