Thanks! Your links are helpful. The idea of using a non-cluster system to build the OFED RPMs was especially useful. The comments appended to the first link have some interesting opinions regarding OFED and maintenance. Like one of the commenters, I too would be thrilled if the Linux kernel shipped with IB drivers for our hardware.
Starting with a RHEL 6.2 x86_64 VM, I've run 'yum update kernel' to get the latest kernel. After rebooting, I ran mlnx_add_kernel_support.sh with no reported errors. This built an ISO including kernel-ib, kernel-mft, and knem RPMs for the new kernel. This gives me some confidence that OFED will build OK on my cluster if/when I update the kernel over there.
Testing-wise, I don't have any spare IB NICs lying around so my least worst option will be to adopt a couple of compute nodes for a few hours. Next, I'd either have to plow ahead with upgrading the rest of the nodes or roll back the updated nodes from an HP CMU image. Testing on a production cluster adds to the challenge, I suppose.
Dave