What worries me more in terms of comments here aren't the people pointing out possible issues with this camera, but the near fanatic herd of holier-than-thou "supporters" (who I'd like to think are paid shills for some other company) describing why this camera is so awesome and what you shoot with isn't in what are possibly some of the most condescending and insulting ways imaginable. No amount of actual insults towards Sigma or negative reviews could possibly hurt the brand as much as its "supporters" are.
OTOH, I'm having trouble imagining which company would waste money on trollish astroturfing given the market performance of the last few Sigmas. Have you people considered calming down, realizing that people have differing opinions, and letting people decide for themselves what they like? Right now you're just hurting the image of the company you claim to love.
I have to say I find it completely hilarious that so many people are complaining that a camera which costs ~$4150 with a $600 battery grip that needs lenses in the neighborhood of $1000 dollars to take full advantage of the sensor is now going to be about $300 more.
You're the same people who are on here bitching every day that nobody should need files that big because your 10 year old computer won't even process 10MP raws quickly, and about how the new Canon doesn't have enough megapixels, and how the NEX7 has too many megapixels, and about everything else that comes along, ad infinitum.
Nobody cares. Kill yourselves.
Since Adobe screwed up their purchase and trial links, and is still charging $99 for an upgrade that is supposed to be $79, here's the LR4 Windows trial download link I found by substituting numbers in the URL: http://trials2.adobe.com/AdobeProducts/LTRM/4/win32/Lightroom_4_LS11.exe