Minor Description
I've seen people using an AttributeModifier to manipulate the ID of a component, causing puzzling problems e.g. with Ajax.
It would be nice to show a warning in the logging in this case, telling him/her to use http://wicketstuff.org/wicket13doc/org/apache/wicket/Component.html#setMarkupId(java.lang.String) instead if they must manually set the id.