Looks like they've replaced the "Internal Server Error - Read" screen with a static message (image below). They've been saying over twitter that the website will be up in "a few hours" for the past 4 hours or so.

I wonder if something major happened behind the scenes that is taking awhile to resolve (like a DDoS attack, etc) or if it is simply a problem of getting enough high level IT staff into the office on a national holiday to figure out what went wrong.

Had to actually call in to Marriott to book my room for tonight since I wanted to use a specific rate code. I can't remember the last time I made a hotel reservation directly with Marriott over the phone!