The marketing mavens at Microsoft, Sun Microsystems, Novell, IBM and Apple Computer are looking at the removal, by a rival, of support for older operating systems as an opening to a "year of opportunity" (Steve Ballmer's words at Microsoft's recent Partners Conference) for moving corporations to new server operating systems.
With Novell pushing users to give up NetWare, and Microsoft dropping support for Windows NT, we see the incredible sight of these two companies believing they can "steal" customers from the other! Even Apple is jumping on the conversion bandwagon, with Steve Jobs chortling that "the time is right to try to win the hearts and minds of the disenfranchised Windows Server base".
Here's the actual situation, though. You're running one or more servers with a no-longer (or soon to be no-longer) supported network operating system such as NetWare 4 or Windows NT 4. You have three choices: 1) keep what you've got; 2) upgrade to the latest version of that network operating system (NOS); or 3) scrap it and go with something new.
If what you've got is working and, more importantly, you're using it because the applications you run aren't supported on any other platform, then stay with what you have and ride that horse as long as you can.
If, on the other hand, you decide it's time to step up to a more current NOS, do you scrap all your training and knowledge, throw out your hardware and switch from NT to, say, AppleServer or from NetWare 4 to Solaris? There's nothing wrong with moving from one NOS to another, provided you do it for good business reasons (new features, better heterogeneous integration and so forth). But jumping to a brand-new, unproven (in your environment) system with at least a steep learning curve for the software and possibly a huge expense for new hardware is cutting off your nose to spite your face. Sure, you're upset that (Novell/Microsoft/whoever) has cut off official support for the old system you use. Yes, it might be tough to go to NetWare 6 or Windows Server 2003 - but Solaris? AppleServer? How dumb do the marketeers think we are?