There is a lot of buzz today about Media Queries. The technology works very well on browsers that support it and it could eventually become the industry standard.
One of the problems with Media Queries is that Microsoft didnít support it until their release of IE9 in February of 2011, so a large percentage of todayís visitors to your site will come there with an older non-supporting browser.
But the real problem is that Media Queries was designed by those on the Academic side of the net. Their concept of new technology is that if you donít have the latest browser it is your fault that you canít view a website and you should just upgrade. They view backward compatibility and an upgrade path as totally unnecessary evils.
No business person in their right mind would turn away 12% to 20% of their visitors, their potential customers, because they didnít have the right browser.
The academics also decided to change the format of the media tag in the CSS links to include the queries. As a result, if the non-supporting browser recognized the word screen in the media tag, but not the query, it would activate every CSS file at once. If it did not recognize it as screen it would turn off every CSS file; great from the Academic viewpoint, horrible from the commercial viewpoint.
What if they had split out the query in a separate attribute and changed the rel definitions to use alternate stylesheets for the non-default CSS files. If the browser did not support Media Queries it would not know what to do with the media attribute and would rely on the rel tags to determine the default CSS files. If it did understand the media attributes, it could use them to activate or deactivate the CSS files according to the query results
You can use Variable HTML on a business related site today and it will support a greater number of potential customers. Best of all, what you learn using Variable HTML will be completely transferable to your eventual use of Media Queries when and if you decide to make the switch.