How to stream transactions on the network How would I go about getting a stream of transactions broadcast on the Bitcoin network? Is this supported by the vanilla client? 

I know that the client can notify me on new blocks and on all transactions that effect an address in my wallet, but I want to stream ALL transactions on the network.
Reading your question again, and looking at the comments, I think your question is slightly misinformed.

The standard bitcoin QT client is a node, which means that it receives the inventory of all transactions and relays all valid transactions it requests to receive (from the inventories). That's a bit of a mouthfull but read it carefully.

This has nothing to do with your wallet. It is a standard function of the full node on the peer to peer network.

What you appear to be mixing is the functionality of the wallet and the functionality of the node. These are two different things.

Bitcoin QT is unlike other (lightweight or SPV) clients which only request information specific to the addresses they hold, when trying to syncronise themselves with the network.

If you are looking to essentially print all transactions that are being relayed through your node, I think this would be pretty straitforward using something like Node.js or just running a continuous regular process which queries Bitcoind using RPC.