There will always be some items or services more valuable than bitcoins. Let's imagine. The HD6990 is valuable item today, so is the Bitcoin. The 6990 will lose it's value dramatically in next few years, the Bitcoin will gain the value slowly. You assume that none will trade the long-term valuable bitcoins for short-term HD6990. But this is false. If you get very lucky deal such as 4 BTC for HD6990, you will buy it today no matter what the price will be afterwards! You can do the job and earn additional bitcoins or whatever to get the 4 BTC on your account again. And You will have the 6990 also!

The slow deflation of Bitcoin is not a flaw in any sense, it's additional bonus! If people want Bitcoins, they wil ltrade goods and services for it. Only value of goods and services will determine value of Bitcoins.