Kickstarter is a good idea, because it weeds out bad ideas, and gives funding to good ideas on a mass scale. You do see some good accessories and a few standout products like the pebble watch come up, but a truly great idea is relatively rare.
I feel like it has the potential to change "small" tech. As you said, we see accessories and watches, although we haven't seen a smartphone or iPod replacement. Those things are very complicated for a small company or individual to get right, and to get people to want it.
I personally haven't invested in any projects, as its tough to know if a company will deliver on its products (and usually international shipping is pricy), but I do like the fundamental ideas behind it and the effect it is having on the market
Kickstarter does exactly what it should (and TgD mentioned), weed out lame or strange, ridiculous projects and focus in on the good ones. It means that companies don't have to take gambles but can rely on pre-sales and investments from the actual customers. Pebble is the prime example of that. Something on a large scale (a phone, tablet, etc.) will probably require far more capital and investment than Kickstarter can generate. And a much bigger ecosystem of support.