Novell is just used by network managers who hate Microsoft....
what real company these days uses Novell!?
Not every company replaces its computers yearly
2003 server is no great shakes either - keeps grinding to a halt when busy
Most companies replace on a 4 - 5yr cylce for servers.
Windows 2003 makes an excellent workgroup to midrange server. If you're getting it slowing down big time, you need to investigate why, and fix. I would argue that w2k3 is faster than the similar NetWare (NetWare 6/6.5) which gets bogged down in the standard Linux way under load. And, the forum VM is hosted on a w2k3 server

NetWare was a great product back in its early days (v2 - 2.2 was a little unstable at times), but due to old, ill considered architecture, any process could abend the server (in the same fashion as 16 bit Windows apps) - Cheyenne (now CA) ARCserve used to be a big one for abending the servers. They fixed the architecture in v5 to help, but it took a huge performance hit.
NDS was a brilliant directory, but Novell found it difficult to provide a use for it.
I have fond memories of NetWare 2.2,3.11,4.1 (not so fond v5 and 6!), but these are old, unsupported, unsuitable (today) systems. Time to move on.
w2k3 is being replaced early next year with Server 2008, and not before time (2003 R2 was just a minor update).