The City of Seattle is very pro-tenant, so you have that in your favor.
You might start by downloading some of the info the City provides regarding landlord-tenant issues. Visit: http://www.seattle.gov/dpd/Publications/Landlord_Tenant/default.asp
You'll be looking at things like "Just Cause Eviction". A new property owner cannot just evict because they feel like it, and they are limited in the amount of increase in rent that they can impose (as I recall, it's capped at 10%).
You can determine who exactly purchased the property by searching for info at the County Assessor's office. Look for the link to Excise Tax Affidavit towards the bottom of the page. The property owner info will give you the tax parcel ID, which can be useful in your research. http://www.metrokc.gov/assessor/eRealProperty/Disclaimer.asp
You can determine if any new projects have been granted a permit (by the DPD). Sometimes it takes a little poking/stumbling around to find the exact permit info. http://www.seattle.gov/dpd/permits/
A developer has to grant a certain amount of advance notice of eviction, and it can be tied to whether or not a permit has been granted.
All that being said, you might also contact attorney, Will Wright, a Biznik, "diverse"-friendly and more.

