In the article: IE 7.0: Missing the Search Boat?, Susan Kuchinskas takes comments (or lack thereof) by Bill Gates about the "full" update Microsoft's IE 7.0 with a strong focus on security. The article also discusses at the rumored browsers from Google and Yahoo! and the problems they might cause for MS.
There's another good reason why Microsoft should do more than add security to IE 7.0, according to JupiterResearch analyst Joe Wilcox: Search rivals Yahoo and Google are both rumored to be working on their own branded browsers, while Netscape is testing a new prototype. Right now, about half of MSN's revenue comes from ads shown on search results, Wilcox pointed out. "Start getting a bunch of new browsers out there pointing to other search engines; that has an impact on MSN," he said.