After watching the first episode, I can honestly say I like the clippy-cloppy sound their hooves make when they walk.

The foley department must have went through a lot of coconuts.
It's certainly beyond cute, and has a level of quality I did not know existed in little girl's cartoons. I thought it would be something like a direct-to-DVD Barbie movie, but instead of being driven purely by spectacle (as in, the only selling point is that it has Barbie in it) it feels as if they are really trying to set up characters with both strengths and flaws as well as some "interesting" pony-lore that they'll hopefully stick to. I'd definitely say it has the level of quality that other Hasbro toy line TV series have - GI Joe and Transformers, and if that continues they'll have a definite hit on their hands. It comes off as a bit more mature than the lucrative sugary cereal crowd (6-10 year olds) that I would expect them to be aiming their merchandise at, and appears to be for the preteen/tween market.
It's very interesting that Hasbro seems to have mined a formula out of their TV shows (GI Joe and Transformers) and are now applying it to My Little Pony as well - and it seems to be working, if older male viewers are as obsessed with this show as I am lead to believe. Whatever coven of warlocks Hasbro hired as their market research team must be making extra sacrifices to their dark gods in celebration of their continued success. Mattel could certainly learn a thing or two.
I also laughed out loud (or "LOL'd", if you will) that the apparent main character's name is Twilight Sparkle (voiced by the lovely and talented Tara Strong). She's an antisocial pony (I'm pretty close to loathing myself for using that word) who spends all her time reading. So when she turns down some other ponies (self-loathing achieved) who want to hang out because she needed to go to the library, it was more than appropriate that I thought to myself "Can't socialize, obsessed with crappy book series!"
Is that a coincidence? I don't think so.

I don't think I'll continue viewing this show (it just doesn't hold my interest) but if I you happen to know any preteen girls, I'd recommend this show to them if I were you.