I... I don't know. I'm curious as to what shows are getting ignored due to 4chan not noticing them. I was under the impression that MLP was getting all this attention because there just aren't shows like this coming out often. MLP is unabashedly happy and colorful and cute and girl-friendly, but doesn't readily (or purposefully) insult viewer intelligence. Kind of like how Powerpuff Girls or W.i.t.c.h. were (except W.i.t.c.h. was stuck on a channel nobody fricking watched.)
Along with PPG, combing my recent memories offhand, Kim Possible and Totally Spies also ended up being international phenomena and merchandising successes (one due to its snappy writing and likeable characters, the other due to... hell, I have no idea.) For non-girl-aimed stuff, one needs look no further than Avatar, and while that had 4chan backing, it didn't need it to get popular with all ages and genders. 4chan was also hardly the only place to pick up on MLP and spread the word about it, and I wouldn't place the credit solely on /co/ for turning people onto the thing--especially after the first few months.