Me, I love Discord. Much like Pinkie Pie, he gives the writers
carte blanche to come up with as many insane physics-defying gags as they can, which is always fun to see. And John DeLancie does such a great hammy job with his voice acting that I can't help but laugh at just about everything he says.
I don't really have a problem with Twilight becoming an alicorn, either. After all, she's extremely talented when it comes to magic, even if she doesn't like to draw attention to it. It makes sense that this would be what she was building towards as Princess Celestia's student. And gaining wings certainly hasn't changed who she is and how much she geeks out when it comes to reading.
Personally, I think the writers have something in store for Twilight later this season - maybe Celestia is preparing her for some big cataclysmic event that she suspected might be coming soon, something that requires alicorn magic to solve. Even if the change was mandated by Hasbro, I'm confident that the writers will be able to craft a good story around it.
People have bashed Season 3, but I've just started watching it and I think it's great fun so far. Admittedly, I'm only three episodes in at this point, but the two-part "Crystal Empire" episode is probably the most inventive and engaging season premiere they've done (even if we didn't get to know King Sombra all that well), and "Too Many Pinkie Pies" is easily the hardest I've laughed all week (and a great spoof of Flanderization to boot)
And finally, while I do respect Lauren Faust greatly and applaud her for turning MLP into something genuinely entertaining, I think some fans put a little too much emphasis on whether or not she'd do things differently if she were still on the show. I liken it to "Mystery Science Theater 3000" - Joel left in the fifth season, and it still continued to be hilariously funny for the rest of its run. The departure of the creator does not necessarily mean the show is no longer valid. Fact is, the remaining writers still do a fine job of keeping the characters likeable and interesting and funny, and at the end of the day, I think that's the most important thing.