Agreed a very relevant video indeed a setup such as this one is exactly what my colleagues and I need. We really need a large sever like the Apple Xserve or something similar. I wonder what the running costs for such a machine are...
Unless you have > 2-3 workstations and a relatively fast LAN ( >= 4Gbps ), you don't need a "larger server" like that. Perhaps that many storage drives, but the "head node" on those disks doesn't have to be large.
Your "old, too slow" Mac Pro could probably pull the weight if drop the proper networking card(s) in and attach a pool of disks. Running costs would be higher than something newer and sized appropriately.
That video dates from 2010. That XServe he is pointing to probably could be equaled by a quad mini with two small SSDs for mirror OS ( and if have to secure rack it: stuffed in http://www.sonnettech.com/product/xmacminiserver.html )
If capped by a 1GbE to the clients then just a raw Mini is capable. If using bonded/aggregated 1GbE for more speed an TB enclosure with a 2 or 4 port 1Gbe card would work open up the bandwidth but likely not going to get out in front of the standard configs for a quad Mini.
Or could use a mini as a XSan metadata controller and get another box that just puts raw blocks on a fast enough network to the clients.
If one was to make a thread asking questions about storage solutions where would be the best place for one to post?
If use a Mac Pro as the "head node" to the Storage solution this forum would work. ;-) If want dedicated hardware then if looking for a range of opinions versus SAN/NAS set-ups then that likely has better thread over in a place like creative cow's SAN/NAS threads or maybe http://www.smallnetbuilder.com/