It's a nephew!
My first, too. I've just spoken on the phone with my brother - and it's a nephew! He was born yesterday evening after a long labour (poor sis-in-law!) They don't know what to call him yet :D Typical of them, they take their time with the important things. And no visiting until later in the week - they want to take it quiet and get their "sea legs" as parents first so to speak (he's their first).