The question is this, if everybody is thinking like me, won't that mean the value will keep going up as more and more people hoard bitcoin?
Why would my spending using bitcoins be impacted by your decision to save your bitcoins?
Sure, fewer of your coins for sale on the market means the exchange rate is today higher but if I want to buy something, say ... a new laptop on BitcoinStore.com, why would I be more or less likely to do that just because you happened to not spend your coins?
Additionally, while not entirely a hassle for me to cash out my coins, it is an extra step. So if I already have bitcoins or I receive bitcoins as income (e.g., dividends from some stocks I might own, or maybe a really good string of luck on
http://bitZino.com) then I'm more likely to patronize a bitcoin merchant than to cash those funds out and use the cash proceeds to make my purchase. If I want to replenish my stash of bitcoins using dollars, I can always do a trade using Coinlab or something like that so that I can spend my bitcoins yet at the same time maintain a level of savings of bitcoins that doesn't change much over time.
The only problem with "hoarding" is that if the exchange rate were to head the other direction, those whose only interest in Bitcoin is for speculation then start to bail out and dump their coins. This introduces exchange rate volatility which isn't a desirable property of a currency.
The thing is though, this increasing exchange rate is helping significantly to fund quite a few Bitcoin-related startups. BitPay just raised another round of funding, for instance, in which investors include those who have benefited from a rising exchange rate (fueled by your hoarding). As a result, the rising exchange rate is helping to build a stronger bitcoin economy.
Another way the rising exchange rate is helping is by creating liquidity as well. A year ago, at a $120 million total dollar valuation (of all bitcoins combined) a company wanting to buy and send $25K USD worth of bitcoins to a supplier would have had an impact on the exchange rate -- order book depth was pretty thin and a $25K buy was a big deal. Even worse, the supplier that received the coins would then go to cash out and that same $25K worth of coin would clobber the exchange rate in the other direction. So a larger valuation allows larger transactions to occur efficiently (less of a whipsaw effect from larger transaction sizes).
So your hoarding helps bitcoin to gain traction.
Thank you for hoarding.