Document gotcha with :is and DOM props (vuejs#2402)

Author: ferk6a

src/v2/guide/components.md

@@ -603,6 +603,8 @@ In the example above, `currentTabComponent` can contain either:
 
 See [this fiddle](https://jsfiddle.net/chrisvfritz/o3nycadu/) to experiment with the full code, or [this version](https://jsfiddle.net/chrisvfritz/b2qj69o1/) for an example binding to a component's options object, instead of its registered name.
 
+Keep in mind that this attribute can be used with regular HTML elements, however they will be treated as components, which means all attributes **will be bound as DOM attributes**. For some properties such as `value` to work as you would expect, you will need to bind them using the [`.prop` modifier](../api/#v-bind).
+
 That's all you need to know about dynamic components for now, but once you've finished reading this page and feel comfortable with its content, we recommend coming back later to read the full guide on [Dynamic & Async Components](components-dynamic-async.html).
 
 ## DOM Template Parsing Caveats