I personally don't mind if Samsung is going down but I doubt they will fall flat on their faces anytime soon. I prefer LG but even if say LG and Xiaomi become just as popular as Samsung, I probably would get sick of them too. Like watching an underground band become mainstream and you get sick of their songs.
But I am glad different sites are reviewing different brands now too. Two years ago for Android phones, it was generally Samsung, LG, HTC, Motorola, and the occasional Sony device that rarely makes it to the major US carriers. Now I see reviews for Xiaomi, Meizu, Lenovo, ZTE, Gionee, Oppo/OnePlus, and so on. I like to see variety. Wuth 7 billion people in the world and a bunch of brands out there, our planet shouldn't be ruled strictly on iPhones and Galaxy. Imagine if 90% of car owners either used a Hyundai (Samsung) or a Dodge Viber (iPhones)?
The coolest looking phone I've seen recently surprisingly came from Lenovo, a brand I am not too fond of. The Lenovo Vibe Shot rear design looks very cool.