I am one of those people who drinks hot coffee in the summertime. If it's too hot for hot coffee, I'll opt for soda if I want caffeine, or just skip it all together. Occasionally, I'm in for iced tea. But iced coffee? Never.
Basically, it has been my experience that the icing of coffee exaggerates coffee's most negative aspects, especially its bitterness. It often has a bit of an earthy/dirt flavor when it's cold. Part of this has to do with the fact that many cafes put coffee in the fridge, whether when it's fresh or after it's gotten a little old. Even if it's fresh when it goes into the fridge, it stales while it's cooling. And if it goes in stale, there's just no hope at all. I know this because I've worked for a couple of different coffee houses, chain and independent, and almost everyone I know has worked in the coffee industry at some point, too. I used to worry, when icing down the coffee, about watering it down. Some customers wanted it super strong. Then again, I would get customers who complained the iced coffee was too strong. It seems you can't please everybody all the time.
Today, I got my iced coffee from Tully's, and basically, it was hot coffee poured over a lot of ice. So probably half coffee, half water, by the time I started drinking. I added a little half and half and Splenda, as I would with any cup of coffee (I only drink it black if I know for sure it's really good--and even then, I'm not usually in the mood for so stark a flavor). What I discovered is, with iced coffee, you actually want it watered down. The extra water in my cup seems to have diluted the iced coffee bitterness (for the most part). Plus, the coffee was at least relatively fresh when it went into my cup, so that helps.
I don't know if I'll ever be a huge cold coffee drinker. When the coffee cools in my cup, I still won't keep drinking; I'll either reheat it or toss it (I am an unapologetic coffee microwaver--I know that shocks some people, but I don't drink coffee incredibly quickly and unless you burn it, microwaved coffee is fine). But maybe there will be times in the summer when I go out to coffee with friends in the afternoon and I won't be the black sheep who orders a Coke instead of an iced mocha or whatnot. Then again, it's kind of fun to be a black sheep sometimes.