They will. Nintendo have already dealt with other online cheaters, there's no reason to assume they won't deal with these ones.

Whether a patch is applied client side or server side, you do still have to code it, debug it, and test it to make sure it won't cause more problems than it solves.

I quit playing The Conduit online because of the amount of time it took to just get into a match. My online time available to me is short nowadays. But 2 nights ago, I was playing and when there's a cheater/hacker, I quit after the match and find another room. 2 nights ago, Out of three races in three rooms, I was stuck racing with a cheater/hacker. It pissed me off. So much actually that I'm getting tired of having to deal with it. I've pulled the game from my system and haven't put it back in since then. Guess it's time to finish my copy of Manhunt 2 finally. This cheating is just such total horse sh*t. If Nintendo isn't coming down harder soon, I'm done with MK Wii. And I know I can play offline but I've finished everything in the game already as single player. Online was the last bit of fun left to the game for replay value. And now that's gone.