Is it possible that sometimes Wikipedia steals Wikinews' thunder?
You get something like that kid (not) in a balloon and it struggles/fails to get on Wikipedia but I assume did OK on Wikinews.
Sometimes a current event is big enough that Wikipedia can cover it without fear of deletion (I think of Katrina) and I seem to recall the coverage in Wikipedia was amazing.
Perhaps that means Wikinews can only ever be a little brother because Wikipedia gets to cover the big stories as well as Wikinews ever will.