Email is also pretty featureless. An open standard will always innovate slower than a proprietary site.
The issue with email is that innovations have to be adopted independently everywhere for them to be widely useful. But that doesn't have to be the case. You can structure a decentralized system so that any user of the system can deploy innovations on it, that the other users can immediately benefit from, without requiring them to be standardized.
*Google Wave enters, stage left.*