It turns out that even those who work towards a new Web monoculture will have a hard time achieving that. PPK recently tested several browsers based on WebKit, and concluded that "there is no WebKit on mobile". …
Much as I hate to disagree with them, I feel honour-bound to point out that there is no “WebKit on Mobile.” There’s iPhone WebKit, Android WebKit, S60 WebKit (at least two versions each), Bolt, Iris, Ozone, and Palm Pre, and I don’t doubt that I’ve overlooked a few minor WebKits along the way.
What seems to be happening in practice is that the various companies that are using WebKit as the basis for their browsers are creating numerous different forks, with wildly different results. And what other choice do they have, as long as Apple remains the dominant WebKit contributor, and the development is often controlled by Apple's needs and release schedules?
So you end up with different browser engines, all based on WebKit, but with all those companies investing in WebKit browsers having to invest a lot of money into creating and maintaining their own forks. Suddenly there are a lot of browser vendors out there!
Maybe they will solve this problem in the future. Apple's control over WebKit could be on the downturn, and different browser vendors could come together to create the "WebKit dream" where everyone is in sync, and forks are unheard of.
However, I doubt that will happen any time soon.
And if it does, my point still stands: Monoculture on the Web is bad!
And for now, monoculture certainly seems like it's a long way off.