There's no doubt that iSCSI is an effective and inexpensive way to connect to a storage area network (SAN), freeing up scores of small businesses from the hassles of direct-attached storage (DAS).
But sometimes praise for a new technology can go a little overboard, which is why I want to direct your eyes to this article at ComputerWeekly. Not only does it do a good job of pointing out some of the drawbacks to iSCSI (higher Ethernet latency, loss of available ports), but it highlights some of the extra networking goodies you'll need to get it to work properly (TCP/IP Offload Engine, high-performance switches).
This isn't to say that iSCSI is a dog. Quite the contrary, as mentioned above, it's both effective and economical. It's just that sometimes we in the press get caught up in the hype, born partly out of a desire to constantly be on top of new developments.
And the poor user doesn't become acquainted with the downside until after the check has been cashed.