Depends on the admin tool support. One of our NetWare admins runs Linux but he needs to keep Win2K in VMWare for some of the tools as they either don't work at all (mostly just the older stuff like nwadmin for the older servers) or they don't work quite right (I think the DHCP plugin was one that didn't work quite right, but don't quote me on that). The new stuff is almost all Java so it can be made to work with a little work, it all depends on how persistent you are =)
The main consideration to think about is "can I do everything I need to". This includes things like reading mail too, because there's no free Exchange client for Linux and I have no idea about Novell's mail stuff. If you're setting up the mail stuff too you could just enable IMAP and use that, but it depends on what you want/need.