If demand continues to increase and supply is constant, then yes. But supply is not going to be constant, that's a wholly unrealistic assumption. Already, alternative currencies and online wallet services are increasing the effective supply of Bitcoins.
If an Altcoin is reasonably predictable valued at .1 Bitcoin, why should I care whether you give me 10 Bitcoins or 1 Altcoin? (The value might go up or it might go down, but so long as they're equally likely, I don't much care.) Thus each Altcoin increases the effective supply of Bitcoins.
Similarly, I don't care if you give me 10 Bitcoins or a Mt. Gox code to claim 10 Bitcoins. Thus Mt. Gox codes act as Bitcoins as well.
Once shorts are available, interest-bearing accounts will be possible. This will allow the two sides of a short to cancel out, require no bitcoins, and the long side will also act as a supply of Bitcoins. I may consider a promise to pay 10.2 Bitcoins next month just as good as 10 Bitcoins today. I may consider a promise to pay the value of 10.2 Bitcoins next month in US dollars just as good as 10 Bitcoins today. (Assuming both promises are backed by an exchange and tracked as exchange assets.)