Storage via NAS, etc.
Having looked into NAS for storage a time or two my impression remains that there are less complicated alternatives, unless needing all its capabilities. Not necessarily solutions more elegant, only something not unduly taxing one's brain if just wishing simple storage.
If memory serves, for those wishing to go this route then Synology would be a good choice. However I also recall mention of NAS systems not always playing nicely with iTunes; photo libraries may also be a problem.
Using a Time Capsule can be a simple if imperfect solution. With wi-fi built in, it is basically just plug and play. Wi-fi speeds are sufficient to perfectly stream iTune HD movies. One downside would be cost: there are less costly alternatives. Another is that the TC is designed for dedicated Time Machine backup; it cannot be partitioned, and if used for Time Machine will by default continually overwrite the entire disk. So if using one for storage, forget about Time Machine backup with it.
Other external hard drives can of course be partitioned, which will allow their use for both Time Machine backup and separate storage on the same disk. One will likely need to go this route in any event, TC or not, due the need for the safety of all data backed up in two separate places. While one could use but one drive with the redundancy offered by Raid 1, there can be issues at times, and it still leaves all one's valuable data in one location. Preferably the data would be backed up in two physically different places, or at least two different drives in the same location (hopefully not flooding or burning down).
Offsite storage with a paid third party might work great, if not a viable option unless with fairly fast internet.
Also consider if 1TB will provide enough storage. It seems a lot, but if many HD movies will quickly fill. One might wish a bit of breathing room, and enough space for at least that conceivably used in the next few years. By which time technology will have marched on. Even now Thunderbolt is a possibility, but expensive. High transfer speeds can be great, but even those relatively low can stream video. That no more than USB 2.0 will work, with lots of storage options with that standard. Increasingly so with USB 3.0, if one wishes to think forward some.
External hard drives of 2TB capacity, 4TB and more, can be had for relatively modest sums. Figure on two of the same to insure redundancy, unless going with Raid. But if Raid, look into the particulars closely: something like a Drobo can work fine, but reviewers point out various potentially serious problems, as well as just being fairly slow. One reason to aim for higher capacity is simplicity: one larger drive will appear and be used as a single unit, whereas numerous smaller capacity drives daisy chained can by nature not resemble one whole (or at least not easily).
In sum, a Time Capsule can present a quick (if somewhat expensive) and easy storage solution. At least until you've exceeded on it the capacity of your computer's internal hard drive; then one will be considering the need for redundancy. If contemplating NAS, then prepare to do some serious research on best configuration.
Digital is great, the intricacies of its proper storage not so much.