For me the exciting bit is being able to access devices from them.

E.g. I've been waiting for this for a while because you can write an app which communicates directly with an Arduino or any other serial device.

This means that a lot of special purpose desktop apps communicating with custom hardware can be written as Chrome apps and take advantage of the speed/ ease of UI development of web apps.

For one of the apps I maintain this will reduce the time it takes to make UI improvements from several days to several hours.

Chrome extensions have had access to external devices for a long time. It's not often used, but I've done stuff implementing chrome + arduino.

http://developer.chrome.com/apps/app_hardware.html

A quick google search shows: https://github.com/BertHartm/Chromeduino

Absolutely, I've also done some proof of concepts like that but for production use the "in browser" experience didn't really cut it for my uses.

"chromeless" Chrome windows have been in Chrome since the start as far as I can remember: Tools > Create Application Shortcuts.

This has never actually been implemented on OSX, which surprised me when I switched from linux, I missed it a lot

It looks like they open up APIs that otherwise wouldn't be exposed, like access to the shell and devices.

Cool, Java Applets reborn

I don't see much wrong with the concept behind Java applets. Small downloadable apps that run on multiple platforms, backed by a universal runtime.

The execution was awful, but still.

More like ActiveX components reborn, because these things will only run in Chrome. Much like ActiveX only ran in IE.

They run "on" Chrome, not in it. A separate icon, window, etc. You need to have Chrome installed, but it's different from ActiveX in that you're not going to see "plug-in missing" in the middle of a page somewhere.

Great, phonegap for the desktop :(

Well, Activex was windows only. At least you can run in three big platforms now. And probably Android later. This is not activex, perhaps Adobe AIR is kind of similar, but it was not web centric.

Chrome extensions have had access to external devices for a long time, including both USB and Bluetooth.

http://developer.chrome.com/apps/app_hardware.html

NPAPI has been available for awhile, too.. Not sure if that's what they're referring to when they say shell access.

https://developer.chrome.com/extensions/npapi.html