Question : DHCP with two domains

Ok here's the situation.

We've created a new 2003 domain (in a new forest) with 2 DCs running DHCP and DNS.
The old domain already has DNS and DHCP running but we want to enable DHCP and DNS in the new domain.
On the DNS servers in the new domain we have a zone transfer setup so the dns zone [org.whole] from the old domain is able to be looked up on the new DNS servers. The new domain uses a different zone name which is [org.local].
In order for machines in the new domain to be able to contact servers in the old domain by short name we have created aliases in the new org.local zone to point to the FQDNs of the servers in the old domain.
What I want to know is how to enable DHCP on the new servers because there are two sets of DHCP/DNS servers using different zones.
If we enable DHCP on the new servers in the new domain then clients in the old domain might pick up a lease from the new DHCP servers and acquire the DNS settings of the new domain, causing them to register in the wrong zone.
We need co-existance because we are doing a gradual migration of users.

Thanks in advance.

Answer : DHCP with two domains

AFAIK, running two dhcp servers on the same physical subnet is ill-advised, but you could probably pull it off if your DHCP server(s) (or maybe a local firewall running on the DHCP servers) can be configured to only accept requests from particular MAC addresses.  Then you can just move machines over one-by-one by disallowing the MAC from connecting to the old DHCP server and allowing it to connect to the new DHCP server.

I know linux could handle this, but I'm not swearing that this is possible under windows (sorry, I'm not a windows geek).

Cheers,
-Jon