Proposal for upgrading the Ethereum VM with wasm

Hello,
I wrote a proposal today for upgrading the Ethereum VM with wasm. You can
see it here https://github.com/ethereum/EIPs/issues/48

One of the harder parts of fitting wasm to Ethereum is the current Ethereum
opcodes CALL and CALLCODE.  CALL makes a call to another Ethereum contract
(module) and the result is placed in memory at a specified location.
CALLCODE is kinda like dlopen. It injects code from a given contract into
the current running code. Currently I don't know of anyway to support this
kind of behavior with wasm semantics. So if we adopt the proposal we will
have to modify the wasm VM some.

Please let me know if you have comments or suggests!

Thanks,
-Martin Becze