Tamiflu effectiveness

In Feb 2008 My 7 year old son got very sick and lethargic in just a matter of hours. I brought him to the pediatrician and he tested positive for type b influenza.  He took Tamiflu the same evening he first had symptoms and by  the next morning, he was acting perfectly fine. It was amazing how quickly he recovered. This gave me some comfort last year with the bird flu worries, after seeing how effective Tamiflu was with regular flu.
Recently,I read that the influenza virus is very resistant to Tamiflu this year. Has Tamiflu actually helped with the swine flu? Does the CDC think the swine flu will develop resistance to Tamiflu quickly?