JustinS posted a comment asking about the difference between a thin client like Sun's new Sun Ray 170 and alternative devices. I specifically mentioned Wyse in a previous story. This is the form factor for their Winterm S30 and their Winterm S50. The S30 runs Windows CE 5.0 while the S50 runs a Linux distro with the 2.6 kernel. In my opinion, these aren't "thin clients" at all, but rather "embedded" devices.
In contrast, the Sun Ray does not run a conventional operating system. It doesn't run embedded Windows, Linux, or Solaris. There is enough logic on the Sun Ray to support a TCP/IP stack and display graphics. That's it. All of the work is done on the Sun Ray Server. With version 3.0, the server can run on Solaris or several Linux distros. I personally plan to run Red Hat or Fedora. You can confirm my claims by reading the Sun Ray Overview .pdf.
You could argue that the Sun Ray is running some sort of operating system, but I would counter by saying it's much more limited than Windows CE or Linux. Simple = more secure. Microsoft publishes security patches and service packs for Windows CE and Windows XP Embedded. Sun only publishes patches for its Sun Ray Server software. With a Wyse terminal, you may find yourself needing to patch their so-called "thin client." Patching dozens, hundreds, or thousands of "thin clients" sounds the same as patching general-purpose PCs. With the Sun Ray, you let a real thin client sit on a user's desk while you only patch the Sun Ray server.
I'm not arguing the Sun Ray is the answer to everyone's problems, but I do see it as being several steps towards the right direction.
Update: I just read Network Computing's review of "remote-display servers." These include products like Citrix Metaframe. Unfortunately, NWC mixes the term "server-based computing" with "thin clients" throughout the article. Here's the deal: all of the so-called "thin clients" in this story are PCs running Windows 2000:
"For our performance tests, we set up 30 workstations running client software to connect to each of our five display servers. These workstations were all members of our test Active Directory domain, and each ran Windows 2000 Professional."
These workstations run special clients to connect to centralized servers running applications like Microsoft Office 2003 and so on. So, instead of having to install Office on every PC, you use the copy on the central server. This is a step in the right direction, but I would encourage NWC and others to avoid the term "thin client" when talking about these products and instead focus on the term "remote-display computing." These Windows 2000 desktops aren't thin at all; you still need to patch and secure Windows 2000 on every box.