There are two things that should happen.
Developers should stop coding vendor prefixes by hand & vendors shouldn't add any more prefixes into production releases.
I agree with Remy Sharp that other vendors including -webkit vendor prefix support is bat shit crazy.
Developers should stop coding vendor prefixes by hand
This centralisation of vendor-prefixing is what is needed. As support is added in browsers Compass can be updated to include new prefixes all without you having to change source code plugging in all the holes.
Vendors shouldn't add any more prefixes into production releases. "Non-production ready browsers should support experimental prefixes, production ready releases should not." - @rem
The prefixes should be kept to nightly / beta builds for testing purposes only. That was the intention for them anyway, those really interested in testing the features and giving feedback will and we won't have this problem going forward. This means the CSS working group will need to standardize these properties fast so they can hit the stable releases.