Yes, Borderlands' GOTY will include all four DLC with the game by the price of 50 bucks.
Borderlands is a good game and since it includes four DLC of 10 bucks/800 MS, this is a fantastic deal, not to mention in includes the fantastic eagerly anticipated game Duke Nukem Forever demo, which makes it more EPIC! And guess what? It's an exclusive...so regular foes won't get the demo for a long time! ^^
My personal opinion? Like I said, it's a great deal but since I already have Borderlands and it's four DLC....paying 50 bucks(40 bucks for PC) for the exclusivity of a demo it's not worth it, not even worth for the awesomeness Duke Nukem is.
Oh, those whose are wondering why does it include that demo? Well, Duke Nukem Forever is being made by GearBox, who created Borderlands and published by Take 2(2K), which published it.
But yeah, have 50 bucks(40 bucks for PC) to spare and never played Borderlands? Go for it!