We will soon open Gnosis to any oracle. For this we are working on a standard to describe events and how to resolve them.
The general idea is that it will not be necessary to write results on the blockchain. Instead the oracle only singes messages that describe the event/ the result of the event. The big advantage is a) scalability and b) a potentially even higher (logical and technical) separation between prediction market (and other applications) and the oracle. One example would be a price feed of all stocks on the NSAQ - with the signing only method the numbers can be published in principal every hour/minute/second/… All those data are available and only those that are relevant will be written on the blockchain. Since the results are signed and the signature can be checked on the Blockchain anyone can write the results on the chain.
The process would be:
a) Anyone can create an event description.
b) Oracles can sign that they are willing to resolve this event
c) when the event happens oracles sign the outcome.
All the details are here in a first draft: Ethereum Oracle Standard - Google Docs