1) The business applications stuff (e.g. Siebel, etc.): Virtually all of that has been re-written into Java, or is accessed via a terminal program client on a mainframe or via a web browser, over the past ten years at the major Fortune 5 companies that I am familiar with. This stuff runs as well on Linux as anywhere else.

2) Unified API: Linux *has* a unified API. It's called POSIX. Linux implements the entire POSIX API. Linux has two GUI API's (GTK+ and QT/KDE), but since both are installed on every Linux system in existence today, that's irrelevant. When I was part of a team that wrote a major enterprise application for Linux, we used GTK+. We could have used QT just as easily. It just didn't matter.

3) "enterprise class" software distribution: Unix has had this for years, and Linux is just a re-implementation of the Unix API. All the "enterprise class" Unix software distribution software is also available on Linux. Google runs tens of thousands of Linux nodes to search the web, surely you don't think they're doing software distribution *by hand* on those tens of thousands of servers?! Personally, when I was managing several hundred Linux and Unix servers, I used 'rsync' and ssh to handle the software distribution. This required about 30 minutes of scripting time on my part, after which software distribution was a case of pressing a button (I could have automated it, but we didn't want to do that for reasons of quality control -- software didn't go out until it'd been vetted on a test setup).

4) Configuration management tools: I'm not quite sure what you're talking about here. Large-scale Unix and Linux deployments are comprised of entirely identical systems, to the extent that even every byte on the hard drive is identical (with the exception of swap file and /tmp areas, of course). Anything user-specific lives on the server. There's no configuration to *MANAGE*. I can log in to any workstation on our network and be at my desktop. When I was managing a network of several hundred systems, I kept some spare cloned hard drives and systems hanging around. If a user's system went down, it was a case of go to the user's desktop with a new system on the cart, yank the old system out, put the new system in, turn it on, and after it finished booting the user was back up and working with her desktop and files and all.

5) Desktop "profiles" -- all Unix/Linux user management is done from a centralized location. All non-standard Unix/Linux software is installed in a centralized location (on the file server). Typically providing for different desktop "profiles" is part of the standard process of creating a user, where you decide what user groups he's going to be a member of, and from thence Unix enforces the access priviliges (if he's not a member of the group that can access CAE applications, for example, he doesn't even *see* the CAE applications or the directories that hold them, much less be able to run them). The Linux/Unix machines themselves are bog-standard with a standard software load that does not vary from machine to machine -- everything that is user-specific lives on the server, and a user can go to any workstation on the network, log in, and be at his desktop with his settings and his applications.

Look, us Unix geeks were doing this with Sun equipment back in 1989. Linux is no different from any other Unix when it comes to ability to manage large-scale deployments -- it's been done, it's old hat, there's hundreds of thousands of Unix sysadmins who could do it in their sleep. The fact that hard-core Windows guys know nothing about this is a testament to their ignorance, and has nothing to do with the limitations (or not) of Linux.

BTW, the biggest issue I have with going to Linux workstations rather than a proprietary Unix workstation: Maintaining standard system configurations. Unix hardware tends to remain standardized over a long period of time. But if I buy a video card today for a PC, it will be discontinued within three months as the manufacturers continually improve video cards. What I end up with, as hardware attrits, is a mish-mash of hardware rather than an easily-administered standard configuration. But the Windows guys have the same problem, so it can't be said that this is a reason to choose Windows over Linux.