If MS changed their browser so significantly, many websites would break. A doctor's office I support uses dozens of web sites for insurance, lab results, hospital admissions, etc... I would have installed Firefox or Chrome on all the PCs if the web site worked properly on those browsers. The ugly truth is that many government and corporate systems _only_ test their sites in IE. Its a shame, but thats the state of the industry. If MS changed to WebKit, many of their enterprise customers would feel pain.