There is one very big reason for Google to do this, and it's not what many Slashdotters think. Anybody using Firefox or Chrome has Google as their default home. Anybody using IE has MSN as their default home. This is a war over who gets to propagandize you with their ads and collect your personal information. There is no good/evil dichotomy here if that's what you're looking for. Further, I'll end with a categorical statement in order to offend people: Anybody with strong feelings about which web browser is the best is probably spending too much time surfing the web, and is in fact suffering from an internet addiction. IE 7, Opera, and Firefox are all pretty similar from a normal end-user perspective.
effectively using the internet is NOT internet addiction!! making sure that the web experience is the same no matter what kind of machine you are on is not too much to ask neither is it even close to internet addiction!!
A committee takes root and grows, it flowers, wilts and dies, scattering the seed from which other committees will bloom. -- Parkinson