In the short term it's a bit of a problem, but I imagine bitcoin's deflation will settle once the "boom" phase as finished, and as the currency matures. There'll be a flat deflation of X% per year/month/whatever, and e-commerce/trade solutions just need to take this into account, and adjust prices once a day automatically.
Completely agree, the rates will stabilize and have none of the wild swings foreign exchange currencies do, just by virtue of the supply limit. Exciting times.