"ZOMG ALICORN TWILIGHT THE SHOW IS NOW RUINED FOREVER!!1!!"
Okay, I'm exaggerating slightly, but only slightly (that reaction has mainly been a feature of sites like Equestria Daily and /mlp/, and the discussions at places like here and the Round Stable have been almost entirely devoid of alarmism and fanrage, instead focusing on actual discussion about it).
Yyyeeah... I had a fairly thought-out response to the finale which I posted to my FIMfic blog. In the interest of laziness, I'll just copypaste it here. I'll go ahead and put it in a sblock while I'm at it so I don't dominate people's screens.