I think the price will continue to slowly fall as long as there are early adopters willing to sell.

Forget terabytes of internet traffic.  A real useful metric would be one that Theymos regularly calculates: number of unspent generations.  (or in other words, number of coins that have been mined but have never participated in any transaction, as determined by scanning the blockchain).  Last time I asked him, that figure was 2.4 million BTC, with over 3/4 of those coins being before block 70000 (in other words, mined before July 2010).