This helps to explain the buyer enthusiams we are seeing in Seattle: With a few exceptions for entry-level homes, interest rates are not yet so far from the low that a previously excited buyer will not buy something. But, they have moved far enough from the low to create additional urgency.
Cool regionally adjusted numbers in the body of the article (the 10.5% accounts for the less robust markets in the US). http://www.forbes.com/sites/trulia/2013/06/14/buying-cheaper-than-renting-til-mortgage-rates-hit-10-5/
Pretty in-depth and dynamic Rent v. Buy analysis from Trulia, including adjustments for interest rate/hold period/tax deduction