Plus if the desired result is supported in CSS3 then you can use javascript to just trigger the change via CSS instead of performing the task through the script

Plus if the desired result is supported in CSS3 then you can use javascript to just trigger the change via CSS instead of performing the task through the script. An obvious example of this is transitions. If you have CSS3 transitions you can trigger them with a class name change instead of using jquery's animation code. When you can do that you don't need jquery or other library at all. Unless you have simply awful HTML that requires an advanced selector engine, such as Sizzle as you state. But as you point out, if the devices listed have unreliable support of javascript then chances are it has unreliable support of CSS3. I don't understand the argument against building a shim as a proof of concept though. What's wrong with building the example to see if it becomes popular in traditional uses of CSS before pushing it as a standard? Don't bother since it might not work on TVs because of lack of proper javascript support?