I do not see Google making a good case here... MSN Search is a Microsoft product, as is Internet Explorer 7 and Windows. Microsoft has the right to promote its own products, and so far there is no evidence that Microsoft prevents or impairs use of Google or any other search engine.

Microsoft does not appear to care that Google is the default search engine for America Online's client software, Mozilla Firefox, Opera, Konqueror, and Safari. It can be difficult to add MSN Search to these browsers as well: in Firefox, it took as many as 6-clicks and skimming through several pages to add MSN Search (it is now down to 2 clicks, with more simple pages).

Before you compare this to the Netscape versus Microsoft antitrust lawsuit back in the 1990s, understand it is a bit different. The case did not get traction till the issue of Internet Explorer using secret Windows APIs came up. Microsoft could use these secret APIs to make its browser faster; since they were secret no other 3rd party would be able to use them. It gives the Microsoft product a distinct, unfair advantage: it's an abuse of power as a monopoly.

So far, there is no evidence of Microsoft doing anything like this in Google's lawsuit.

I think it's pretty clear Microsoft and Google are at war. And because everyone and their grandmother uses Windows, Microsoft will win. Of course, this will change if Google decides to introduce their own operating system, and can market it well enough so that a significant amount of people switch to it. Things are going to get interesting...