If I had a dime for every time a new weathercaster, anchor, reporter, etc pronounced "Rockwall" as "Rock-WELL"...
Then again, I once had a back-woodsy kinda neighbor who told me she just LOVED those "Norman Rock-WALL" paintings...
Other cute mispronunciations over the years:
Collin County: CollinS County
Cresson: Cruss-SAUNNN (like 'Croissant'...did that myself a couple of times, and boy, the phones rang!!)
Waxahachie: WOCKS-hat-chee (Warren Culbertson, who lives there, used to butcher it that way himself!)
Ennis: EEEE-nis
Kerens: Karens (locals know it as "kerns")
Grand Saline: Grand SAY-leen
Wills Point: Will'ses Point
Hebron: HEB-rohn
Westminster: Westminister
Mexia (of course)
Terrell: Tuh-RELL
White Settlement: "Whitesville" (ok, that was a joke Shirley "What's Happening?!?" Hemphill made on the Tom Joyner Show years ago when the show was local!)