I guess some actors you're just used to hearing with the one accent...like say John Barrowman or Gillian Anderson and it's so odd to hear them naturally speak in another. I don't find it as jarring with David Tennant somehow as I did with Barrowman.
It's making me smile to think my daughter will be one of those cute little girls with an accent that used to make me all broody when the tourists came to Yankee Candle, LOL.