I think it all really started with the Pebble smart watch two or three years ago. This company started out on kick starter with a watch that would pair with your phone and could send updates about your text messages, incoming calls, and other sorts of stuff. Since then, it seems that everyone is coming out with a smart watch, even Apple. Apple is rumored to be releasing an "iWatch" some time later this year so I thought I would give a list of some of the things I would like to see in a smart watch.
A conceptual mock up of an iWatch I found here: http://www.macrumors.com/roundup/iwatch/
It has to be a stand alone device. While you aren't going to get an entire phone on your wrist, the watch needs to be able to work with out a phone and need to be able to work with different kinds of phones (or different kinds of iPhones since it's an iWatch after all)
Some kind of built in iPod. This kind of relates to the stand alone thing. I think you could easily put in a couple of GB of music storage and basically have an iPod shuffle on your wrist. Then you could either listen over bluetooth speakers/headphones, or even have a headphone jack in the watch.
Music control of your phone. Basically it lets you brows your music library on your phone (or even your computer) and then select songs to play and do all the normal music control stuff.
Needs to be water proof. That should be pretty obvious. I don't want to have to put my watch in a bag of rice after every time I wash my hands.
Phone alerts. So it basically tells you when you have a new text message or Facebook notification or anything else that currently send you a notification on your phone.
Responding to text messages. I think putting siri on it (or a bridge to the siri on your phone) and letting you reply to text messages with your voice could be pretty cool and useful.
Health monitoring. It would keep track of your heart rate and your activity levels and basically do everything the Nike fuel band and other fitness bands do right now (essentially putting them out of business, which is probably why there are a ton of Nike fuel band ads right now. They're trying to sell as many as possible before everybody just buys and iWatch instead).
Battery life. At the very, absolute least, it needs to last all day. It would be even better if it could go a full week with out needing a charge. It would also be cool to see some kind of induction charging so that you can just take it off and put it on a mat to let it charge over night. Might make things simpler
That's all I can really think of at the moment. It would also be really cool if it came with an open SDK so that other developers could design their own iWatch apps.
Anyways.
I hope you enjoyed that little read and as always, thanks for reading.
-Matt.