June 30th, 2010 is 93 days away (8,035,200 seconds for fans of Rent).  Lack of indicators, to the contrary, make us believe that you have until then to close any contract that allows you to take advantage of the federal home buyer tax credits.  A short sale is unlikely to qualify in that time frame (though not impossible) as the approval has to take place on or before April 30th. You must have both an accepted offer AND close before June 30th to qualify for the Credit. It is not an either or.

A search of RMLS for Portland real estate reveals these statistics:

There are 5188 active/bumpable listings in the city of Portland.
694 of them are short sales (13.3%).

2990 of the active/bumpable listings are under $300,000.
562 of them are short sales (18.8%).

There are 216 active/bumpable listings over $1,000,000.
4 of them (1.9%) are short sales.

I still maintain that the Home Buyer Tax Credit is not THE reason to buy a home now but it, and the factors required to qualify for it, should be a part of the current decision making process.