If I have my MacBook plugged in to a monitor, can I close it?

I'm going to be buying a 13" Pro in a few days and I have an external monitor question. If I have my Mac plugged in to a monitor to watch a movie or Hulu, can I close it? Will it keep playing or will it Sleep?

Your machine will sleep. You can always wake your machine up again with the lid closed by either removing or plugging in a USB device but that isn't a good idea as part of the cooling of your MBP will be done through the keyboard.

I think you can also set it to not sleep when you close it, if I am not mistaken.

Thanks for the help. I'll play with it when I get it.