The Chromebox does support dual-display output, but right now it will only mirror the desktop image to both displays, rather than extending a single operating environment across multiple screens. Again, the system chooses the output resolution automatically, in this case opting for the highest common resolution between both monitors.
Along with connecting a monitor to the Chromebox, you must also provide your own mouse and keyboard. That opens up a larger discussion about device compatibility, which is less of an issue for the Chromebook considering its built-in Webcam and input devices.
Six USB 2.0 ports on the system (two in front, four in back) imply broad support for the vast ecosystem of USB devices. I did not expect the Chromebox to support every esoteric peripheral, but I was also surprised by how quickly I found devices that didn't work.
With the very first Logitech mouse I connected, the affordable G300, the cursor arrow shot off to the side of the screen every time I moved the mouse or clicked a button. Every input device after that one worked fine. I tried mice and keyboards from Razer, Microsoft, and Logitech. I was even able to use the wireless Logitech Touch Mouse M600.
I had a harder time using USB Webcams. I tested Webcams from Creative, Logitech, and Microsoft. The Chromebox recognized the camera in all cases with no trouble, but the Chrome OS does not currently support USB-based microphones, which made for some silent video chats (sorry, "Hang-Outs"). Google says USB microphone support is coming in a future release, and that for now you should use the analog microphone/headphone jack on the front of the unit. That works well enough, but it would be preferable to use the Webcam's own microphone.
Connecting a printer to any computer without specific driver software can be difficult, but fortunately Google's Cloud Print software provides an effective network-based workaround. Instead of getting mired in printer testing, I tried connecting an external, USB-based DVD burner and a multiformat USB media card reader. The Chromebox recognized the files on both storage devices. The system does not include DVD player software, so it cannot play DVD-based movies.
I wouldn't call any of the hardware compatibility issues I encountered "show-stopping," but they do add the potential for various levels of inconvenience to using the Chromebox. The mouse problem is easy enough to solve -- buy a new one. But for the Webcam audio, not everyone would willingly endure wearing an analog microphone to video chat. Google says it is working on the problem, but in general it speaks to the fact that the Chrome OS is still very much a work in progress.
With so much activity on the Chromebox taking place online, the impact of the hardware on overall system performance is limited. That said, I still found situations where you might want faster processing or better graphics capability. Gaming, for example. Among the recent additions to the Chrome application store are Bastion and From Dust, two stalwarts of the downloadable game console market. Bastion worked reasonably well, although mouse response felt a bit sluggish. From Dust would not load at all. When I tried to load it, an error message informed me that my graphics chip wasn't powerful enough.
This is an interesting case of two Google initiatives meeting up against each other. From Dust lives on the Google Chrome Web Store thanks to Google's Native Client technology, which effectively creates a browser-based environment in which you can run a piece of software designed for another platform. The game plays just fine on a standard PC with a reasonable graphics chip running the Chrome browser, but there's no way to know that the game won't play on the Chromebox unless you read and understand the recommended system specs on its Web Store listing.
I did not try every single application in the Chrome Web Store, but I expect that From Dust is not the only one that won't work on the Chromebox.
By itself, the Chromebox's Web-focused, Google-centric experience is not necessarily bad, particularly for those who have achieved, or aspire to achieve, a simple cloud-based computing life. The problem is that the Chromebox is a newcomer in a largely Windows-focused world of software and peripherals. Its newness offers would-be buyers the biggest challenges. I felt the absence of some basic features after using the unit for only a few hours. Google says it is addressing some of those things, but I'm sure I haven't uncovered all of them. You or your organization might also have reasonable trepidation about putting your entire computing existence in the hands of Google.
If you're willing to make that leap and endure the growing pains of an operating system in active development, the $329 Samsung Chromebox offers an attractive, low-risk entry point into Google's great Chrome OS experiment. It has pleasing looks in a bleak sea of budget Windows midtowers, and its very nature as a desktop will ease your transition to an operating system that requires a constant Internet connection to be useful.