Attic space has always been one of the best places in the house for long term storage, but it has its share of problems as well. Poor insulating and ventilation and cramped space make it less than ideal for storing things like CDs. However, with the proper use of storage boxes you should be able to store just about anything.
Many attics in the United States do not have insulation, especially if the person who built the home was under a time or money budget. People don't usually go into the attic unless they're putting something away or getting something out, so why spend the money to get it insulated? But this leaves it unable to accommodate storing certain things - digital media for example, is not designed to withstand the extreme temperatures that many attics will go through.
Ventilation can be another problem as well. Unless you live in the desert, moisture will build up over time, which will dampen everything when the temperatures drop in the fall. This is why you need to put your things into storage boxes. Clothes will get moldy, toys will change color, and wood will soften and rot when sitting out in the attic, season after season. The boxes will act as a guard against it, and keep things safe.
The cramped space of an attic also makes arranging your storage boxes important. You can't just throw things around and expect to find it later, or be able to add more easily. A box's cube shape helps with this arranging, and so will go a long way in making your attic more usable.
So whether is clothing, or toys, or even cd storage, an attic can be a convenient place to use, so long as you have it properly prepared with insulation, ventilation, and a good storage plan. Without this planning however, you're just inviting disaster to strike, and it probably will.