The biggest thing Google could do for the mobile web is force carriers onto a quicker Android update cycle.
The implementation of CSS media queries is broken in nearly all shipped handsets making them pointless as an optimization for sending the correct images to browsers. This isn't likely to change for quite a while.
The Android browser really needs to auto-update like the desktop Chrome.
The phone carriers want control over your phone, they don't want you to be able to easily 'upgrade' without their junk in it; it is in-fact the reason why it takes so long. The situation is helped a bit when users buy phones and plans separately, although it is becoming less popular to do this in my country, I fear. This is what was so good about the Nexus One, Google pushed updates directly.
This argument doesn't stand for OEM devices. And there are many of them with no carrier customization whatsoever (current version of Samsung Galaxy S II), with slow upgrades and no "system components" upgrade.
Google is still pushing updates to the Nexus One and Nexus S, so it's not like it's the past.
By the way what I'm talking about is a limitation of Android itself: it has no package management system (with dependencies, upgrade etc.) for core components. And what I'm proposing would allow certain parts of the system to be upgraded while carrier junk stays there.
Google is actually already doing that for Gmail, Market, Music, Maps and other apps. Why not the browser ? (even if for now it uses a separate libwebkit)
I'm not an Android expert, but I think many libraries (browser, sms, phone, etc.) are basically kernel/baseband dependent (To make an hardware accelerated browser means modified GPU drivers, means new/updated kernel features, etc.), so it's almost impossible to provide an unified build of some apps on current devices (Gtalk video available only on 2.3.4 also comes to mind)
The implementation of CSS media queries is broken in nearly all shipped handsets making them pointless as an optimization for sending the correct images to browsers. This isn't likely to change for quite a while.
The Android browser really needs to auto-update like the desktop Chrome.