To add to what others have said, it seems the overheating issues have been resolved with later revisions of the Time Capsule. Most of the horror stories online are first or second gen (mostly first I believe), and even then not all first gen TCs have died on people.
You can also negate the overheating issue by raising the TC above the surface to allow for air circulation underneath. Some have even gone as far as placing it on a laptop cooler, but I doubt that's necessary.
You can wait, but there's no guaranty there will be a form factor redesign of the TC, so ventilation issues may still persist.