I am not sure what took so long but thankfully RIM has stepped in. There have been a few third parties that have offered up their own icons for developers to use in their BlackBerry 10 apps. Jeremy let me know that RIM has now published their own action icons on the UI Guidelines page of their developer site. This allows any developer to download the 59 icons for their menus, action bars, and more. It also allows developers to stick with the same icons users will see in the native BlackBerry 10 apps.
Check them out at this link by clicking the blue button that says “BlackBerry 10 Icons”. RIM was kind enough to even include a reference Excel file that shows all of the icons with a description.