In the whole backlash of the IE8 announcement, an important piece of information got overshadowed. If you use HTML5, you can skip the effort for version targeting. So, use HTML5 and then you can forget about coding for browsers. I am glad that at least for the developers who are coding for the future do not get punished for past mistakes.
As John Resig explains, you can use
<!DOCTYPE html> and the popular browsers will switch into a standards mode. A big incentive for starting with HTML5, if you are not already convinced about it.
However, I wonder if HTML5 is not going to happen before IE8 comes out. The HTML5 draft was recently announced. And given the adoption rate of the industry for other technologies, including the strict
DOCTYPE, HTML5 is not going to be the one widely deployed anytime soon. So the IE8 meta acrobatics will stay for the majority, which I think is still sad.
To think of it, I do not consider adding that single line of declaration a lot of effort. The problem is with the approach we are taking to solve this problem. The effort gets monumental when you have to track the changes across various versions of various browsers. It is not about that line of code, it is about the default behavior of a popular browser and treating workarounds as permanent solutions.