GR00T: In my situation, although I never complained about the price or discounts (or lack thereof), it's a case of it not being in my favored genre. More along the lines of something I'd be curious about trying if it were the right price.
Yeah, that's me too. Oldskool 2D platformers are not really my thing anymore, so the SK trailer didn't really convince me either, apart from the wonderful music (which unfortunately is apparently only trailer music, the game music is different).
I was still somewhat interested because it gets so much praise everywhere, so I finally bought it when it was on sale a month or two ago on GOG. I've yet to install and play it though, and now this news about new content makes me feel maybe I should postpone it even further, just to get the "complete experience". :)
I should also mention that I liked LIMBO (which is a 2D platformer), played it through a couple of years ago. I liked the art style and the atmosphere, even though in the end the game left more questions than answers (ie. things you see and meet are not explained later; like there was a mystery to solve but it didn't let you solve it).