I run a similar setup to Bernard's and quite like it.
I use 2x Intel 160GB SSDs in RAID0 for scratch. For larger storage on the desktop I use 6x WD Caviar Black 1TB in RAID6. And for networked/long term storage I use a Synology NAS mounted as an AFP share on Mac, NFS on Linux, and Samba on the sole Windows box in my house. I actually do use Linux for some photo work as I happen to like some features of DigiKam better than LR. Having the photos on the NAS proves handy to share files around readily between OSes.
A Synology NAS is far more than just a NAS. The applications and features are unmatched by rivals in this space. If you are only interested in bulk storage, this is a pricier way to go. The extra features, however, can be quite addictive and it is worth taking a look at. Looking exclusively at the performance of a Synology overlooks the value it is capable of providing. Just read a few reviews/showdowns and you will understand better.
10GbE is a rather expensive way to go. ThunderBolt will be a less expensive option if you only need high-speed access from a single desk. SAS is also a reasonable route to consider.
I would consider something like the
Synology DS1812+ a good way to offload files and keep them accessible from a variety of other systems. It also makes a great music and video cataloging and serving system, among many other things (OpenVPN server, Torrent client/server, background file downloads, time machine, client for Windows to do TimeMachine-like backups (which I use for the sole Windows user in the house), and many other goodies).