Why are coinbase transaction outputs greater than reward?
The extra 0.25058085 BTC is the sum of the transaction fees on the block (each transactions fee is the difference between the value of the transaction's inputs and the transaction's outputs). 

As you can see, this block which had no transactions on it, and therefore no transaction fees, had a coinbase transaction whose sum of outputs was exactly equal to the reward (50 btc at the time).