HPCwire ran an article this week comparing the feature sets, roadmaps, and performance (in general terms) of 10 Gb Ethernet with iWarp to InfiniBand and its DMA technology.
10GbE iWARP leverages its heritage to also support acceleration of emerging Ethernet-based storage protocols, including file storage (NFS-RDMA), which is fully supported by the Linux OFED stack. In addition, the Linux OFED stack also enables 10GbE iWARP to out-of-the-box support Lustre networking (LNET). In addition, 10GbE iWARP adapters can also provide concurrent, native support for standard Ethernet protocols such as NFS, CIFS, and iSCSI. In comparison, InfiniBand has had minimal deployments for server-to-storage communications, whether for file or block storage.
Its worth a read, particularly for you manager types, for a quick guide to some of the major developments in Ethernet these days (like RDMA over Converged Enhanced Ethernet, for example).