This is what ripple is in my opinion. It is a company (Open Coin), backed by venture capitalists and rich silicon valley types. They looked at bitcoin and asked,"What's the best way for us to profit from it?"
Their solution was to make an alternate system which they would control. They also decided to create 100 billion xrp, of which their company would hold 50 billion or half.
Ripple is nothing more than some rich people trying to hijack the crypto-currency movement for their own profit. It is completely antithetical to the whole idea behind cryptocurrencies, which is wrenching control of OUR money from central banks and banksters. Ripple just replaces central banks with Open Coin. The whole thing stinks and their system sucks. You wanna place yourself back under a centralized system under somebody else's control then use (c)ripple.
That's a fair, but quite strong, opinion.
Worth remembering that Jed who created ripple also created MtGox, that most people involved are bitcoiners, and that XRP the currency doesn't really matter, Ripple 1 (ripplepay.com) and Ripple 2 (ripple.com) can both be used without needing to pay, for the ripple 2, you can acquire a lifetimes supply of XRP for free easily, and use the ripple system to faciliate the fluidity of your currencies, and form your own trust networks.
Regarding control, the second RippleD is released to the masses, it's already available on request and I know several people with server daemons running, all those arguments are invalid. Regarding centralization, it's decentralized and you can use any currency, even make up your own. You should do some reasearch and checkout ripplepay.com, and the ripple wiki, check the history and motives behind it's creation, before naively believing everything you read.