This has definitely been brought up before (the main thread is here: http://vatoto.com/forums/topic/14048-a-way-to-filter-latest-updates/) and actually, the mods have added it to the list of suggestions they are thinking over.
There are many complications to this, however, on the technical side of things. Not to mention there's the question of priority: even if they do accept it as something they plan to do, where in the giant list of things-to-do does it go?
So while there's definitely a chance of it being implemented, it most likely won't be any time soon.
My words are my own, and do not represent Batoto in any way, shape, or form unless otherwise stated in the post itself ^.^