What I'd like to see in 201X in regard to browsers

Situation 1: WebKit

Microsoft drops all active development on Internet Explorer 9. Instead, they throw their full support (development team) behind WebKit.

Apple, with Safari, and Google, with Chrome, are already behind WebKit. Apple's implementation on Windows, via Safari for Windows, is shoddy at best, and Google's Chrome is a completely slimmed down version. By getting Microsoft's support behind the engine you have an experienced team that has already developed for Windows.

You also have three operating systems covered (Microsoft = Windows, Apple = Mac, and Google ~= Linux), suggesting that users of these systems will have a great experience with the WebKit implementation.

This leaves Mozilla Firefox and Opera out of the mix, but Opera's team has the mobile browser understood, and could bring that to the table, while Mozilla would have extension experience (not that the experience is all that great, but ...). Either way, the only thing that seems to tie Mozilla together is Google's money, and if Google were to withdraw that support, and WebKit were to support extensions as Firefox does, Mozilla/Firefox may experience a peaceful end.

Situtation 2: Standards

Alternatively, perhaps this decade we can see standards being agreed upon, in particular as the HTML 5 'release' approaches.

While they're at it, they may as well join together on the common cause of making the Web a safer place, and together build safe browsers (even if they each have their own).

What will really happen?

Unfortunately, while I'm hopeful enough to have these ... hopes, a decade just doesn't seem long enough for either of these situations to actually occur.