'Does the hub server require 64bit hardware? The only requirements that I have found were the maximum requirements.

Yes, all E2K7 server roles that are placed in production must be on 64-bit hardware. If you have a smaller organization (a few hundred users), you could put all the roles you need (Mailbox, Client Access, Hub Transport, or even U.M.) on a single server. For combined function servers, though, go with at least 2 CPU cores and 4 - 6GB of RAM even if you are supporting a few hundred mailboxes.

First, thank you for your reply. I was scared that would be the answer. I purchased 2 servers for e2k7 with enterprise software with full intensions of clustering with ccr. Then I ran across a note that you can't install the hub on one of the cluster nodes. The problem is now that I need to convence certain people to let me purchase another 64bit system. Two of us went to an Exchange event and the only thing they mentioned about putting on another server was the Edge server. They really pushed the CCR, but fail to mention that the hub can not be installed on the nodes. This brings up the question as to usefulness of CCR if you still can have a single point failure with the hub on a none clustered system. Other than buying 2 systems for 2 hubs, one active, one waiting silent, is there anyway around this? Or, do I already know the answer?

If you cluster a Mailbox role, you cannot install any other roles on the clustered servers. To avoid a single point of failure, you would need to install more than one Hub Transport server. You can install two Hub Transport servers and leave both of them active on your network and they will automatically work together to provide fault tolerance, load balancing, etc. I suggest that you read the documentation provided here http://technet.microsoft.com/en-us/library/aa998636.aspx. You'll find it very helpful in determing how to configure your topology and what hardware is required to support that configuration. david.