That would be useful. I'm pretty sure openvpn uses the OPENSSL libraries, so it might very well improve openvpn performance. That would be a big win. I think the Dell dual xeon for $650 is the easiest solution. It is Redhat certified and requires no 3rd party device drivers for CentOS. I think I will still deploy some of the smaller appliance boxes for purposes other than high performance encryption.
anyway, it requires patching kernel and due that it's a bit complex solution.
maybe your hardware is enought fast anyway..
-- Eero