You do not have to migrate eDirectory to another server in order to run ZCM. You don't have to get rid of NetWare at all, and shouldn't have to install eDirectory on Linux or Windows to do it either. ZCM will use the LDAP interface to integrate with eDirectory.
Do you specifically have NetWare 6.5 SP5 or do you have OES? Just curious, because OES (both 1 and 2) give you the ability to run NetWare services (NSS, iFolder, eDirectory, iPrint, etc) on Linux. If not, just get yourself a copy of whatever version of SLES ZCM is supported on (SLES10 SP2 for sure), install it on a server, and install ZCM there. Quick note: since most, if not all, new Intel- or AMD-based servers have AMD X86_64 architecture processors and chipsets, double-check the docs before you install SLES, to make sure if ZCM will work on X86_64. If not, you'll have to make sure the SLES installer installs the 32-bit version.
You'll want to do the ZCM rollout before you consider upgrading to Win7, because you can use ZCM as a migration/upgrade tool for going from XP to Win7.
The user's home directories should be able to stay on NetWare. The current Novell Client for Vista/7 will handle that for you, and if you don't want to install the Novell Client for Vista/7, you can set up CIFS on your NetWare server and let them access it as though it were a Windows server. ZCM isn't as tied to NetWare or even eDirectory as ZENworks was, so it doesn't rely on the presence of a Novell Client on the workstation. It has its own agents that handle workstation authentication and such, so you could use CIFS and install the iPrint and ZCM clients and continue to use NetWare file and print services without having the Novell Client on the workstaitons. If you want to. If I were in your shoes, I'd want to use the Novell client... but that's me.