Migrating to Windows 2000

As long as the server is being built as a member server only there really is no problem. I have been running a 2000 member server for some time on the domain without problems. The interesting quirks arise when you build up a DC in a mixed mode environment. As for AD, as long as you follow the guidelines for preparing your network for an AD upgrade there shouldn't be any major headaches (you'll find most of those in the preparation).

Several possible issues here.
You mention migrating, so I'm assuming from a NT4 domain.
If you are truly migrating vs. building a Win2K domain from scratch, there is a certain path you need to take.
First, Win2K servers cannot exist as domain controllers in a NT4 domain.
Second, in order for a Win2K server to act as a Domain Controller (DC)(only possible in a Win2K domain), Active Directory (AD) must be installed.
Third, in order to migrate all your user accounts from NT4 to Win2K, you MUST install Win2K on your NT4 PDC (Win2K will prevent you from installing on a NT4 BDC).
Fourth, when Win2K recognizes that it is being installed on a NT4 PDC, it will automatically invoke installation of AD.
Other issues: NT4 BDCs CAN exist in a Win2K domain. All Win2K DCs are essentially equal (concept of PDC and BDC no longer exists in Win2K)(also remember the second point above).
Bottom line here is that you must have your AD design complete before starting.
One other point: while you can certainly create a Win2K member server and later promote it to a DC (once you have an AD domain set up), you cannot MIGRATE a NT4 domain this way.

System dumped my alias. Wanted to repost in case you want to get in touch with me for questions.
Several possible issues here.
You mention migrating, so I'm assuming from a NT4 domain.
If you are truly migrating vs. building a Win2K domain from scratch, there is a certain path you need to take.
First, Win2K servers cannot exist as domain controllers in a NT4 domain.
Second, in order for a Win2K server to act as a Domain Controller (DC)(only possible in a Win2K domain), Active Directory (AD) must be installed.
Third, in order to migrate all your user accounts from NT4 to Win2K, you MUST install Win2K on your NT4 PDC (Win2K will prevent you from installing on a NT4 BDC).
Fourth, when Win2K recognizes that it is being installed on a NT4 PDC, it will automatically invoke installation of AD.
Other issues: NT4 BDCs CAN exist in a Win2K domain. All Win2K DCs are essentially equal (concept of PDC and BDC no longer exists in Win2K)(also remember the second point above).
Bottom linehere is that you must have your AD design complete before starting.
One other point: while you can certainly create a Win2K member server and later promote it to a DC (once you have an AD domain set up), you cannot MIGRATE a NT4 domain this way.