Of course the week after I buy a Time Capsule, Apple significantly drops the price of the 1-terabyte unit and introduces a model at the old price point with double the storage capacity. Fortunately I haven't even unwrapped this particular unit yet, so I am going to return it to Amazon and get a replacement at a much better price.
My other worry on this front is the possibility Apple will release some sexy new tablet device in September--a rumor in wide circulation on the 'Net and in the press right now. An article I read today referred to such a product as a potential "Kindle killer"--not exactly what I want to hear as the proud owner of a still relatively-new Kindle 2!
In January 1998 I was very excited to own a Newton MessagePad 2100. I bought it just weeks before Steve Jobs killed the product and Apple abandoned all further development.
I suppose one can't worry about timing technology purchases, but you don't want to be the last one to adopt a product just before it becomes obsolete!