You can't make a horse drink the water, but you can sure as hell lead him to it. What's the point of going forward in browser technology with advanced engines like Webkit and Gecko, if we still allow stupid, uninformed users to visit our websites in IE6 without any interruption?
Then all web standards are redundant and we can just go ahead and make browser-specific websites, which ultimately will become online applications. I would say, educate your user, after all, if you don't, who is going to do it?
We have made a conscious decision here at our design studio to alert IE6 browser-users that their browser is too old and that they should upgrade. We have not encountered any problems so far.
One should take into account that if you are hired to develop specific IE6 web applications, then you really don't have a choice in the matter, but if you are part of a design studio developing forward moving websites implementing new technologies or advanced Javascript, then I would say forget about IE6.
After all, the internet is full web developer handiwork and if we decide it's over, then the revolution will come.
// edit
If you want to make stuff a little easier for yourself, using CSS, start using BrowserDetect.js CSS browser detection. It's initialised using jQuery and simply adds a browser-specific class to your body tag on load.
In other words, if you're running Safari 5, your body tag will look like this:
<body class="browserSafari browserSafari5">
This enables you to create browser specific CSS styles without any hacking of sorts.
That was my last 2c.
