It was clear to me back when the FCoE bandwagon was just warming up that Broadcom, with their position in the LOM (LAN on Motherboard) market, would be a curveball that those pushing hardware CNAs would have to contend with one way or another. Frankly, I expected Broadcom to add FCoE to the firmware in a replacement for the 57710 that already has support for RDMA, TOE and iSCSI.
By instead making a bid for Emulex, Broadcom's management showed they understood the FCoE market better than I did. FCoE is the VTL of storage protocols, letting us use Ethernet for transport while still looking to the host and SAN management software like we were running on a Fibre Channel SAN, just as a VTL lets us use disk for storage while looking to our backup software like we were using tape. So the Emulex or Qlogic API is as important as a Windows Storport driver.
Being a network guy for many years, I forgot to look at FCoE as an over-worked storage admin. Basically, Ethernet folks don't have to manage NICs and can take interoperability for granted. Ever since 10Base-T was adopted in 1990, any two Ethernet products could be counted on to connect and work together. Vendors may have proprietary extensions like Cicso's Etherchannel, but when 802.3ad provided a standard method for bonding Cisco added it as an option. Some features like jumbo frames need to be supported by all the devices in the net to be used, but vendor specific implementations are rarely a problem.
In short, unlike their Fibre Channel brethren, Ethernet users don't stick to NICs on their switch vendor's HCL. In fact, there's so little demand switch vendors don't even publish them. In contrast, FC network operators remember all too well the days when an HBA from vendor A would demand 24 buffers but the switch from vendor Q would only offer 16 and the connection would fail as a result. Today's FC market -- with just 3 switch and 3 HBA vendors owning over 95% of the market -- has pretty much solved incompatibility issues. But SAN admins, trying hard to avoid yesterday's pain and tomorrow's finger pointing, stick to certified devices and have less choice than their Ethernet brethren. So Qlogic didn't have to buy Ethernet street cred. We would have believed the Qlogic Ethernet part of a CNA would work, and quickly heard if they didn't.