Raw Transaction RPC calls for bitcoind

I submitted a pull request yesterday that implements low-level "raw"
transaction, and am looking for feedback on the API and help with
trying to test/break it.

Design doc:  https://gist.github.com/2839617
Pull request: https://github.com/bitcoin/bitcoin/pull/1456
Test plan: https://secure.bettermeans.com/projects/4180/wiki/Raw_Transaction_RPC_Test_Plan

Playing around with this API on the command line I'm pretty happy with
the level of abstraction and the way it interacts with existing RPC
commands; for example, "createrawtx" is just like "sendmany" in the
way outputs are specified.

The signrawtx method is the key new method; it takes a raw
transaction, signs as many inputs as it can, and returns the same raw
transaction with signatures. Typical usage would be:

Funds are sitting in a multisignature transaction output, and it is
time to gather signatures and spend them.

Assumption: you know the multisignature transaction's [txid,
outputNumber, amount].

Create a raw transaction to spend, using createrawtx.
Use signrawtx to add your signatures (after unlocking the wallet, if necessary).
Give the transaction to the other person(s) to sign.
You or they submit the transaction to the network using sendrawtx.
I don't imagine anybody but very-early-adopters or ultra-geeks will do
this by calling these RPC methods at a command-line. They are really
intended for people writing services on top of bitcoind. The service