I'm a Bay Area resident that just got back from my first visit to Portland. It's an amazing city, great food, and pinball in every bar. But the weather sucks (I'm still wet), and it's missing the critical mass of tech that the Bay Area has.
The tech scene reminded me of nearly any other similarly sized city in North America. One or two interesting employers (New Relic, Puppet Labs), and the rest is enterprise.
And even if Google, Facebook, Apple, and all the other smaller interesting companies moved there overnight, the cost of living would skyrocket overnight too, blowing away Portland's main advantage.
And if you thought the hipsters' resistance to tech in SF was bad, I feel that Portland's would be worse.