If mining goes from a model where the lion's share of hashrate (and thus bitcoin revenue) belongs to a handful of heavy (100k usd+) investors into early ASIC/fpgas that will subsequently grab most of the newly minted bitcoins, does that really make the whole bitcoin thing "decentralized"?
Yes, because "most" isn't the same as "all". The big miners earn more than the little miners, but the little miners still get something, in the same way that big companies like Walmart make billions, but that doesn't stop you making a few extra bucks at a garage sale. Also, remember than mining is a
business, in which miners sell their computing power for the purpose of securing the network. It is not a get-rich-quick scheme, or a means of distributing money to random people, or anything else. The average Bitcoin user is not expected to mine, or even know what mining is.
In the same sense, does someone who controls 1500 GH/s+ running 24/7 qualify as a "peer" to some guy with a dual 6870 gaming rig that runs at 550 mh/s when he isn't playing bioshock and when his mom needs to access her email?
Everyone running a Bitcoin client is a peer, whether they're mining or not.