You can certainly configure and script the steps that would be required manually, as Log Shipping is simply a copy of your transaction log file taken from the Primary server that is shipped to the Secondary server and then subsequently restored. Just ensure that the database compatibility level of the database on the SQL Server 2008 server is set accordingly.
I suspect however that you may not be able to configure Log Shipping using the Wizards within SQL Server 2000 however, I am not certain on this point. You could of course test this quite easily though.
So just to be clear, you can log ship upstream from SQL Server 2000 to SQL Server 2008 but you cannot Log Ship downstream from SQL Server 2008 to SQL Server 2000
If you want to upgrade the Log Shipping Configuration on a SQL Server 2000 server to SQL Server 2008 then see the following Microsoft Reference