Selecting content type using panels/pages
You can use views for that solely too you know... Don't use a content pane as described below but a page with path /latest-news/%type.

But for panels:
Create a views content pane that gets all types of nodes @ once. Set contextual filter to node->type and choose raw value from url 2.

Create a page in pagemanager with this path:
yourdomain.com/latest-news/!type
Don't set up a context.

Add the contentpane as content in the page. 
Now if you visit latest-news/article it shows all article-nodes. If you visit latest-news/page it shows all page-nodes. 

Now you can have all benefits from panels together with a view.