Regarding the Dash, they are/were devices from Sony running a licensed and tweaked version of the Chumby software, but communicating only with Sony servers.
Regarding the current status of Chumby, the company folded several years ago, though the servers were kept up for somewhat longer by investors in hopes of finding a market. Once that fell through, one of the Chumby employees purchased the bulk of what was left for what I suspect was a nominal amount, put up a server to provide basic clock capabilities while he got things straightened out, then left that basic service up and running and now has subscriptions available for people who want (many of) the previous capabilities of the devices. If you have an old Chumby you should be able to use it as a clock.
Regarding the Chumby itself, it was an Internet-connected tiny-board computer running something Linux based with a touchscreen running applets built in a stripped-down version of Flash. Without an Internet connection, they're not quite bricks but close (there is an offline/serverless setup you can do to run them from a USB stick). The appealing thing about them isn't and wasn't the hardware (basic ARM stuff from before the iPhone existed). The appeal of the Chumby even now is that (as others have noted) it's a clock with some computer features. The Chumby has streaming audio from multiple sources (predefined or manually-entered URLs), an FM tuner, hardware volume knob, snooze button, USB port for a stick with MP3s, etc. along with WiFi and the ability to connect to it via SSH.
These days you can get better software capabilities with a stand and an old Android phone plus a few apps, but even then you're probably going to spend quite a bit more time fiddling with that setup than you will by just plugging in a Chumby, entering a WiFi key, and maybe setting a schedule for switching to/from night mode. And you still won't have a snooze button.