I think it's a bigger jump than just a little optimization. Consider:
* no proper windowing
* no OS support for copy and paste of anything except plain text - you can't
even copy some bold text from one part of an email to another
part of the same email!
* the mouse support is really mouse-simulating-a-finger, with all its clumsiness
(for example, you have to "long click" to get functions you'd normally "right
click" for on a desktop), there's no "mouseover"
* apps are killed randomly in the background and often don't restore their state
upon returning eg: switch from your word processor to your browser and back
again and there's a *chance* your word processor got killed. Depending on the
quality of the code, it'll start up blank, perhaps with the same document, but
almost never in exactly the state you left it.
[1]: https://plus.google.com/100275307499530023476/posts/ViCME1bb...
Hackborn starts with a stick ("I suspect we are going to need to start doing things to prevent you from impacting our app ecosystem") and then shows just a tiny glimmer of carrot ("Doing this correctly, without impacting our app developers... I also think it is something that needs to be done at the mainline platform level...")
So who knows what to make of that. My main reason for hope is that it's just so unusual for Google to speak out that way. All kinds of bizarre things get added to ROMs and they just ignore it. Then this comes and the Google engineers go bananas. It has to mean (or at least, I think it has to mean) that they have some plans around it, and they really don't want something incompatible coming out and becoming a defacto API ahead of that.
One PCs you have right click and double click, which are both replaced with long click. Using PC design interfaces on mobile will usually work (2 becomes 1). But the reverse fails because 1 cannot become 2.
I mean even Microsoft is pushing for full-blown touch interface on the desktop. Android right now is certainly not worse from an interface point of view. If anything it might be more familiar to Windows users because of its more desktop-like UI and icons, than Windows 8's Metro interface is.
For many billions of people Android is going to be their first OS, an OS that is open source, and comes in very affordable devices. Give it 3-5 years and I think it's going to become a real competitor not just in the "mobile OS" space, but in the whole OS space.