Microsoft confirmed it intends to add pop-up blocking to Internet Explorer as part of its Service Pack 2 release, due the first half of 2004. Meanwhile, agencies, advertisers and publishers suggest they'll be ready to kiss the ad units goodbye -- when the time comes. An important question that remains unanswered is whether IE pop-up blocking will be turned on by default. Microsoft said only that it plans to include the feature, and will gather user feedback before announcing further details. "If they turn it on by default, that would effectively kill pop-up advertising on the Web," said Nate Elliott,...