Summary: I have been trying this product for a few days now and I am really disappointed.
Connectivity was easy enough, just plug in the Ethernet cable, power, and HDMI and you're up an running. I did like the fact the firmware can be upgraded directly from the device without PC intervention.
The niceties ended there. The main reason I bought this unit was to work with a D-Link DNS-323 NAS with a built-in AV server. According to D-Link, they should work flawlessly.
Couple of problems:
1. The media stored in the NAS does not integrate into the media categories on the device...music, pictures, video, etc. They only show up on a separate section for media servers.
2. For some reason the playlists I have on the NAS did not work with this device, they showed up empty even though the device is supposed to support M3U playlists. I know the playlist is setup correctly because it works fine with both Media Player and Winamp.
The most annoying problem was that the installation of the included Viiv software for my PC would not run. I would get passed a couple of screens and immediately disappear. I was trying to install it on an HP m8150n Media Center PC running Vista Ultimate.

I contacted D-Link support about these issues and they were not able to resolve any of them or offer any explanation as to why they were happening. I was honestly very surprised about this since I have had very good experiences with their support in the past.

Summary: This network media player is not capable of wireless HD video playback, even if you put it right next to your wireless router. If you plan to use it for HD video, use it via Ethernet, or buy a Pre-N player for that.

Summary: I bought this for two reasons: hi-def video & normal audio (mp3) playback from a 2tb NAS that contains my movies & music. Plugged everything in (ac adapter, hdmi, ethernet cable), & pow, it all worked right out of the box (using Windows XP Pro SP2). The included Viiv software installed & ran just fine for me, no issues there. It's pretty user-friendly & intuitive, but I don't use it simply because I'm either watching videos or listening to music & have very lightweight apps for those (so I don't really have a need for this app). I'd recommend this product if you know exactly what you're looking for & it'll fit the bill.