The previous approach involved a case statement for dispatching commands. The new one enforces a convention between the name of a command (e.g. 'plugin:create') and the name of the class that will be instantiated to run it (Nesta::Commands::Plugin::Create).
By default (in the default theme) Nesta adds a heading above the articles that are listed on a page, entitled "Articles on Thing" where Thing is the name of the page that the articles are listed on. If you set the 'Articles heading' metadata Nesta will allow you to override the entire heading for a given page. Only themes that call the articles_heading helper method will support this metadata.
Nesta allowed the retrieval via HTTP of any file within ./content through manipulation of the URL requested. Inserting '..' into the file name of an attachment allowed traversal outside the attachments directory, allowing visitors to download any file withing the content directory.
Tilt can render all sorts of templates, including Markdown and Textile. When there are several Markdown processors available, Tilt will use the first one it finds. You can also ask it to use a specific processor, so each site can now use its Markdown processor of choice. See #65.