Ah Dermeister I had misunderstood your question. I thought you were asking if both blades could break at the same time, which I don't know and I'm not sure how to find out. If you are asking can one katana cut straight through another katana and into an opponent at the same time, then yes, though you would probably chip or scrape your own katana while doing so. There are some schools of kenjutsu (not to be confused with kendo, which is the sport variant of swordmenship) that focus entirely on breaking an opponents blade.
Ah and thanks Taneda, and yes I agree