In my opinion, the current browser war isn't really about IE vs. Firefox vs. Chrome vs. Safari vs. Opera. It's really about IE vs. the rest.
Why? Because even though these other browsers come from different makers, from the standpoints of intention and technology, they're all in the same camp - the camp that genuinely wants to promote modern Web standards/technologies, privacy, speed, security, ease-of-use, reliability/stability, consumer-choice, freedom (1, 2), interoperability, crowdsourcing (1, 2), innovation, openness/transparency, and extensibility (with the notable exception of Apple, whose intentions are clearly unclear).
This is as opposed to the other camp (Microsoft), which - in my opinion - probably doesn't have a strategic interest in promoting or implementing some of these principles. This camp is seen - rightly so, in my opinion - as the chief bottleneck that's "holding back the Web's full potential" (at least until IE9 is launched).
The alternative/modern browsers are certainly competing with each other (Chrome might be the biggest threat to Firefox; Firefox might be the most important competitor for Opera), but at a macro level, these mutual struggles are collectively leading to frequent and far-reaching improvements in each of the alternative/modern browsers, resulting in a steady erosion of Internet Explorer's market share.
An implication of the above definition of browser war? Once IE's market share dips below 50%, it'll suddenly become important - both statistically and symbolically - for developers/webmasters to optimize their Web applications and websites to take advantage of the increased speed and other features offered by alternative/modern browsers - even if this leads to a poor user experience for IE6/7/8 users - since the alternative/modern browsers would collectively account for the majority share of users now. And even though none of the alternative/modern browsers would individually have a majority share, they're all the same from both philosophical and technological standpoints, making it safe to treat the collective market share as if it resulted from a single entity.
By optimizing Web applications and websites for modern browsers - without caring (much) for the now-minor and ever-decreasing share of slower browsers - developers/webmasters will be doing good to more people, than they would be doing harm to.