At least all current phishing filters are. Really, what's the point of blocking it in the browser? I get the messages in my e-mail. My mail client should check the links in messages against known phishing sites, and if it detects a phished link flag the message, display a warning, delete it outright, or something.
I'm not saying that browser based filters should go away entirely. They should stick around as a second line of defense. But let's put the fight where it really is.