Could you be a bit more specific about what you were expecting? Did you think they could make it magically shoehorn web apps into a desktop metaphor? What more does it need than just a web browser, given that the whole point of Chrome OS is to be just a web browser?
It's a fair criticism. If the OS is a web browser, why use tabs? They just steal valuable screen real estate. Replace them with a windowing system where each page/app gets its own resizeable window, and you can reclaim some of the virtues of a desktop metaphor.
Are overlapping or tiled windows really that useful for web apps being squeezed in to a low-end 12" laptop screen?
They've got a system for chat windows and notifications to show up on top of the main window, and they've got a full-screen button to hide all the window decorations. The only real use a more complex window manager would have is enabling you to show two documents side by side, but I doubt that the horizontal screen resolution is high enough for that to work with most web apps.
I do think that overlapping and tiled windows are very useful for a 12" screen. They're certainly highly useful and desirable on my 13" Macbook screen.
But how many web apps (or any web sites) are actually useful when reduced to a width of 640px? Almost everything on the web these days is designed for a width that's far more than half of the 1280px that is the widest reasonable estimate for the Cr-48's screen. I've measured GMail, Picasa, and Google Docs as needing 795px, 813px, and 889px, respectively, and Pandora with its ads wants a window more than 1000px wide. If Google's going to show off side-by-side multitasking on a ChromeOS notebook, they'll have to use somebody else's web apps.
If "the cloud" starts to tread on more serious territory and people reach the point where they're willing an able to do things on the web that they would previously use a $1000+ computer for, then Google will have to revisit Chrome OS's basic paradigm. But until then, the main purpose for Chrome OS is to make a true netbook.
There are several applications for OSX which take a website and make it appear more like a native app.
The Windows Start Bar, the OSX dock, the OSX dashboard are all much nicer methods for managing apps than how ChromeOS appears to do it, and they've all been around for years. Google should have come up with something better than these for ChromeOS, not worse.
