Hi Jerry,
Q: Does A CA have be a DC for auto enrollment to work if you are using 2008 CA services with NAP for wireless deployment or can use a member server.
A: No. It can be a member server.
Q: Do you have to update the 2003 schema to run 2008 CA services?
A: No.
Q: How can use PKI and wireless authentication for windows CE handhelds since they do not join the Domain.
A: I am not very familiar with Windows CE. Please refer to http://msdn.microsoft.com/en-us/library/ms926458.aspx.
Q: Machine based cert only using webenrollment? A: Please rephrase the question. I am not sure I understand what you are asking.
Please have a look at the
NAP IPsec step by step guide. This uses a 2003 DC with CA on a member server and also employs autoenrollment for exemption certificates. I think this answers most of your questions above.
Thanks,
-Greg