What are the "pros and cons" of the black Apple TV models? What do they do? Do I need one?

The black 2nd Gen Apple TV and 3rd Gen Apple TV are simple devices that stream content -- iTunes music, video, and photos -- from a Mac or PC, an iPhone, iPod touch or iPad (running iOS 4.2 or later) to an HDMI-equipped HDTV and allows one to pay for movies and TV shows from Apple. Both have built-in support for Netflix, YouTube, Flickr and other streaming services as well.

Like any other purchase, only you can make the decision whether or not a black Apple TV model is worthwhile, but you can evaluate the pros and cons of the device to see if your needs are met. The below may be helpful to make a decision:

Pros:

• Tiny, sleek case design.
• Easy to connect to an HDMI-equipped HDTV and setup for streaming.
• Easy to use interface (although text entry can be quite awkward without an iPod touch, iPhone or iPad).
• Easy to stream iTunes content from a Mac or Windows PC (and iPod touch, iPhone or iPad) as well as support for Netflix, YouTube, Flickr and other streaming services as well.
• HDMI, optical digital audio, 10/100Base-T Ethernet and 802.11n support standard.
• Support for "true" 5.1 channel surround sound and 720p or 1080p video (2nd Gen only supports 720p, 3rd Gen supports 1080p).
• Inexpensive (US$99).

Cons:

• Limited functionality -- does not play CDs or DVDs or have any ability to record programming.
• No cables provided as shipped. Compatible cables have to be purchased separately.
• Does not support older HDTVs that lack HDMI support.
• No official internal storage or the ability to store content.
• Hardware cannot be upgraded -- processor, RAM or storage.
• Limited support for audio and video formats. Discontinued 2nd Gen model does not support for 1080p streaming (3rd Gen does).
• Small selection of rental content on iTunes, no ability to purchase content directly.

Ultimately, only you can decide whether or not you "need" an Apple TV. It's safe to say that it is not a necessity in life, but if you would like a way to stream iTunes content from a Mac or PC (or your iPod touch, iPhone or iPad), to your HDTV as well as stream Netflix, YouTube, Flickr and other online content, and/or are interested in renting or purchasing some content from Apple, the 2nd Gen and 3rd Gen Apple TV make it easy.