Not srs. No one will care about W's if your GPA is good. I have a few and was never asked about them. Just be sure to have a good reason for them if anyone ever asks during an interview.
I had 4 Ws on my transcripts and my cycle turned out fine. But I think it all depends on the context. My Ws were either from freshman year undergrad or from college classes I took in high school. I'm also a non traditional applicant...so my Ws were 8+ years old by the time I applied.