Let me try re-organizing that post...my network is basically setup the same way. I recently upgraded my setup:
1. NAS + Basement Home Theater: I put a home theater in my basement for gaming & movies ($599 720p LED projector = super amazing). The NAS doubles as my HTPC. It's just a basic computer running Windows 7 with a gaming card, some big hard drives, Plex Media Center, and Steam. I use a variety of remote controls for it - Logitech K400 wireless keyboard with trackpad, Logitech M515 couch mouse (factory sealed for use on armrests) for gaming, Xbox 360 controls for emulators, and I'm still trying to decide on a final remote control - I've tried several including the new iPazzports, MELE F10, and Boxee remote. Next one I'm going to try is the new Harmony Smart Control, since it lets you use your smartphone as an IR control via blaster, plus it has a regular dumb remote control: (I have a couple of the older Harmony remotes, one with basic buttons & one with the LCD screen, they aren't bad but I like a dumb remote better)
http://www.logitech.com/en-us/product/harmony-smart-control
2. Exercise TV: I have an elliptical machine setup with a TV for streaming movies. For the most part, I use Netflix, but it also has the Plex app. Some stuff is transcoded, some isn't (I think MP4 & some MKV's are natively supported, or something). Note - the new Roku 3 has a headphone jack in the remote control, which is great for an exercise machine because you can turn your favorite headphones into wireless ones instantly.
3. Living Room TV: This is the one we use the most. It has a WDTV Live Streaming box. Right now I just have this hooked up to a shared folder to get full-bitrate 1080p MKV's (MakeMKV is a great Bluray ripper & encoder btw). You can use whatever as a player - Playstation 3, streaming box, etc., anything that supports DLNA. They also have PlexConnect if you have an AppleTV:
http://elan.plexapp.com/2013/06/04/introducing-plexconnect-an-appletv-client-which-thinks-different/
4. iPhone 4S: Dropbox + Plex. You can stream over 3G/Wifi off-site from your house if you setup DynDNS or something similiar. You can upload videos via Dropbox, then install Dropbox on your server and have it sync to a folder within your shared folder structure that Plex Media Server has access to. Same idea for Android devices, iPads, iPod Touches (via 3G/4G or Wifi):
https://www.dropbox.com/iphoneapp
5. Computer Backup: For continuous file backup, I use Genie9 on Windows and Time Machine on Mac. For image backups (drive clones), I use Macrium Reflect on Windows and SuperDuper on Mac. With the pay-for versions, you can schedule these for overnight backups if you'd like. Just share out a folder over the network (there's some tricks to getting Time Machine to play right on older Macs too).
6. Remote Access: Plex for media purposes, LogMeIn if you need desktop access, and there's plenty of other things you can do like a VPN with FTP for copying files back & forth.
There's a million ways to do this. I chose not to have a Hackintosh or Linux server (despite more stability) because I wanted to play Steam games on Windows (there are a lot that aren't available for Mac yet), so I just consolidated the NAS into the HTPC. I usually run FreeBSD as a file server, which is *extremely* robust (my 2TB RAID 5 model has been running for years and years without a single hiccup, and it now supports ZFS if you want to go crazy with storage), but you can buy 4TB drives on sale for $149 these days, so getting a few of those, installing Windows on a PC box, sharing out folders, and installing regular software like Dropbox and boom, you're done!