Processors keep getting faster, hard drives keep getting bigger, memory keeps getting cheaper. Enterprises want their computers to last longer, too. So you would think that would mean that they would buy something close to the best in order to extend the life of the machine. Frighteningly though, I still hear from companies buying machines that are marginal in today's world. This is especially true with memory: given the price of RAM today, buying less than 2GB should be a crime. Yet I still hear from companies that are buying machines with half of that, or even worse. Maybe you can get by for three years (or more) with a slower processor or smaller hard drive, but limping along without enough RAM should be easy to avoid.
Don't do it, buy more RAM!
So what do you consider to be a mainstream computer configuration? I've been out of the corporate environment for four years now, so maybe I'm a little out of touch, but I would expect to see something like this:
So is that anywhere close to what your company is currently buying? (Replace "Core 2" with "Pentium 4" and put in slightly smaller hard drives and that's what I was recommending four years ago, although it was a tough sell at that point on the 2GB of RAM...)
On a related topic, machines with 4GB of RAM are becoming more and more common. Be aware that if you run an x86 OS on these machines you won't be able to see or use all 4GB. See http://blogs.msdn.com/hiltonl/archive/2007/04/13/the-3gb-not-4gb-ram-problem.aspx for some background information. Note that there are some changes in Windows Vista SP1 to show you that there is more RAM installed but it will still show the reduced usable number. Simple solution: use Windows Vista x64 to get access to all the memory you installed (assuming the chipset supports more).