I have to say, that after owning the game and beating it, I love the new designs. So much in fact, that it's my favorite pair of games in the series so far. As well as the Pokemon being my overall favorites as well. And after I beat Black, I played SoulSilver a little bit. After going through a region with no old Pokemon, I find it hard to like any of the older ones as much as I used to(minus personal favorites). The new Pokemon are so spontaneous and creative.
One thing I find annoying about nostalgia freaks is, they don't know the real meaning of the word "creative". They seem to get that word mixed up the word "weird" or the phrase "out of the ordinary". And they just don't want to admit the fact that these new games, based off of story, graphics, and replay value, are better then the old ones. But, I suppose if they want to continue to play an outdated and poorly programmed(even for it's time) game(AKA, Red, Blue, and Yellow), I see no reason to stop them.
But what REALLY boggles my mind, are the people who won't buy Black or White just because of the new Pokes. I mean, hello, you can STILL use all of the old ones(only difference is, they look better and have nice animations and more attacks), no one is stopping you.