lol at these numbers, the beast is calling


I hear a lot about how big blocks will reduce decentralization and make things harder for I dividual miners.
Can somebody show me some data or a paper to support this?
I am genuinely curious, bitcoin's block size from 1 MB going to 4 MB didn't cause any such issues. Propagation time on Bitcoin is already pretty good. We are not talking about decreasing block times here.
Mining is already pretty centralized, almost no blocks are mined by miners outside of pools... The difficulty is so high it's hard to mine on your own. But even with bigger blocks, how would that prevent someone from mining like he does now? If someone is going to invest hundreds of thousands $ in mining equipment, are we to assume that they can't invest at an internet connection that is at least at ADSL or 3g speeds?