Apple had problems from early to mid 2008 with premature failure of some electronic components that were used in the power supply section of the Time Capsule. The items were manufactured at a problematic facility in Asia. Details are well known in the electronics industry.
Apple responded with a program for affected users. Details are here: http://support.apple.com/kb/TS3351
Over the past few years, we do see an occasional post from a user who has had a failure. That is unfortunate, but nothing out of the ordinary since any electronic product can fail and a certain percentage always will.
Millions of Time Capsules are working fine. We only hear about the problems on the forum....it's like the emergency room at the hospital....everyone has a problem here. This is not the place to make an informed buying decsion, just as you would not make a decision about the general health of the community by visiting the emergency room at the local hospital on a Saturday night.
If you had spent a few weeks in the MacBook forum before you made your decision to buy, chances are....you would not have purchased a Mac. Chances are, you've had good service and chances are, you will receive good service if you decide to purchase a Time Capsule.
One of the great things about the forum is that another user will usually post with a completely different opinion. We may hear from them soon.