Thinking of security, would it be possible to write the platform in a way which prevents the site owners, moderators and any intruders from having access to the funds?
You could generate a new address every time that a sponsor wants to sponsor a project. Then when payment arrives, generate one transaction for every possible outcome (one transaction that sends the bitcoins back to the sponsor, and one that sends it to the developer) but don't broadcast them. After that, you delete the address' private key. When the outcome is determined (bounty should be sent to developer or returned to sponsor), simply broadcast that transaction on the network.
This way, the most damage an attacker could do would be to choose whether the bounty went to the developer or the sponsor. The attacker could never send any of the coins to himself (unless he was the dev/sponsor).
This has a few downsides:
- If the sponsor sends coins to an address after its private key is destroyed, those coins are gone.
- You still keep the private key around until a payment is received.
- All developers must be known before the bounty is moved to escrow. Any developer that appears late in the game cannot collect bounties held in escrow before he started work on a project.
It would be nice if we could create transactions that said to forward all funds sent to one address, present and future, to another address. That would kill problems 1 and 2. (Also useful for ex. importing an untrusted address into one's wallet.) If this isn't possible currently w/ script, it sure would be nice to see implemented. (Bounty anyone?

Gotta love irony.)