1) vendor introduces new feature, tagged with vendor name to not pollute the namespace (e.g. -webkit-foo, or msapplication-TileColor from the OP)
2) once feature becomes popular enough to warrant its permanence, vendors agree on some new standard name for the agreed-upon behavior
3) ???
4) everyone uses the new standard name
The problem with this idea is that step 3 is missing. Browsers can't drop their -webkit CSS support because old pages rely on it, and new pages still use -webkit to work on old browsers. The original name is effectively permanent so there's little incentive to even take step 2, because all that produces is two names for the same thing (e.g. you use an attribute with "apple" in the name to choose the Android icon).
In recognition of the failure of this process, Blink (and other browsers) is using a different approach, where new features are not namespaced; instead, they'll require users to individually opt-in to nonstandard features, under the idea that it's hard for an idea to become permanent if it requires each user to individually configure their browser:
http://www.chromium.org/blink#vendor-prefixes
I am a little skeptical that this will only result in going too far the other way -- new features will wither because you can't experiment with them enough to get enough mass behind them to standardize them -- but at least it's not retreading the known broken path.