Major Description
Currently you can't put a link or text in the middle of a wicket:message. You need to break up the message into 2 parts as text before the link and text after the link.
I've made a modification to the WicketMessageResolver class that allows you to nest child components inside a wicket:message and then reference them from the properties file. For example in the html
<wicket:message key="myKey">
This text will be replaced with text from the properties file.
<span wicket:id="amount">[amount]</span>.
<a wicket:id="link">
<wicket:message key="linkText"/>
</a>
</wicket:message>
Then in the properties file have a variable with a name that matches the wicket:id for each child component. The variables can be in any order, they do NOT have to match the order in the HTML file.
myKey=Your balance is ${amount}. Click ${link} to view the details.
linkText=here
And in the java
add(new Label("amount",new Model("$5.00")));
add(new BookmarkablePageLink("link",DetailsPage.class));
In the browser this will output
Your balance is $5.00. Click here to view the details.
I'll attach a quick start as well as an svn diff.