My wife and I also moved to Portland from Austin, so I have a bit of insight on this. First, let me point out that while the job market in general in Portland is still a bit sluggish, the tech job market seems relatively lively. I don't know any experienced, talented software developers who have been out of work for long. I know a number of them who are freelancing successfully, even, so that's possible here, but I would suggest that before you have built up a local network, it's likely not the best idea. If you are planning to visit here, I would search out the user groups and various technical "networking" groups ahead of time and get in touch. Sign up for their mailing lists, plan to attend as many meetings as you can while you're here and ask direct questions about the "scene."
As for interviews and salaries... salaries, at least in the areas I've paid attention to, are generally slightly higher than Austin (offset marginally by a very slightly higher cost of living here) but lower, in general, than you'd find in the bay area. Interviews are across the board as they are anywhere. Your best bet to find out what to expect for interviews is to find someone who works for the company and try to befriend them or at least get their opinion. These same rules really apply anywhere, honestly, so I hope I'm not telling you anything new.
As someone else mentioned, there are a lot of media/SEO related companies here, but there are also some interesting startups and more established companies in other areas, as well. As with my suggestion above, the best way to find out about the different companies is to talk to people who work there. Users group and (the old fashioned variety of) social networking are really your best opportunity to find out more about them.
Also, as with Austin, I've found that the people who do best in this community are the ones who are not afraid to cross bridges (sorry, slight pun on one of Portland's nicknames). That is, explore communities that maybe aren't directly in your area of experience. Whether that's the data visualization group, beer and blog (which isn't really all that much about blogging), or some group for a language you just barely even understand, give it a try and see who you meet. Chances are you'll start to see some of the same people around town. Seek these people out and get to know them -- they will be your best resource. If you're really determined to do well, get involved in organizing and planning of different events and groups. Before you know it, jobs will be coming to you.