Time will tell.
Naruto: Rasengan and it's variants, Kage Bunshin, Kyuubi Cloak, Toads
Konohamaru: Rasengan and maybe he'll develop some variants too, Kage Bunshin, and inevitably apes and King Enma
I think in time Konohamaru could grow to be at LEAST Naruto's equal. Maybe even stronger as he becomes old enough to be Hokage. Konohamaru is Hiruzen's grandson after all. Hiruzen had nothing special. No special modes, no fusion element, no Kekkei Genkai whatsoever and he was still one of Konoha's strongest ninja. That paves the way for Konohamaru if you ask me