Tom the Architect pointed me over to this article called Transparent Commodity Infrastructure and Web 2.0. Excellent piece.
I especially like this quote here:
Let me use an example: back in 1998 if you were building a web-based startup, you were probably running on Solaris/SPARC and using an Oracle database. You were also likely to be running on some sort of a Java servlet engine (though there were exceptions, this was again the leading edge). This huge apparatus usually required at least 1 of the following: DBA, sys-admin, release manager, and build manager– nevermind all of the consultants and vendor people that it took to solve problems that arose from trying to get everything working together.
Fast forward to 2005. Anyone still using Solaris/SPARC for web apps is either a moron or a depressed Sun shareholder. MySQL and Postgres are now considered “enterprise-grade,” and if you should be so masochistic as to still want to do Java development on the app-tier, you’ve got Tomcat, Jetty, and even JBOSS available to you on your platform of choice.
I couldn’t agree more. So many companies stuck in the 90’s … excellent article and worth a full read.
Bieber Labs 
http://blogs.sun.com/roller/page/jonathan?entry=coffee_and_keynotes
The above link is an email that was sent by Marc Andreseen to Jonathan Schwatz of Sun. The email contains the savings that Marc had seen using the sun hardware compared to Linux.
Makes for an interesting read.
This is an very interesting read. Thanks for pointing it out. It looks like in this case, the hard dollars are on Solaris’ side. I guess the only other cost to consider is the pricing model for the other software used int he environment and administration of the machines.
I know that with our Solaris 9x environments, we use a lot of GNU software, which basically has to be custom compiled / tested / installed by ME. This is work that wouldn’t have to be done on a Linux environment.
With that said, I have to point out that I haven’t even LOOKED at Solaris 10 yet, so this may not even be an issue anymore — even though it is for us.