Find your niche.
What do I think? Honestly, I thought the Generation V Pokémon looked odd when they first saw the light of day, especially if I delve into comparing their designs to the previous generations. I'm guessing that those sentiments sum up the feelings of the original poster, that some of the new Pokémon don't look like Pokémon from the first four generations.
Fans originally had a specific number of Pokémon among the myriad creatures that are surely present in the in-game universe. That's the problem: our opinion of how Pokémon should look like is shaped by the first [relatively] few Pokémon that we encountered for the past four generations. I can't deny how some of the new Pokémon look different design-wise. Yet I agree with most of the people who responded to this thread; Pokémon don't have to look a certain way, they just have to be identified as Pokémon by the creators.
"So what are Pokémon supposed to look like?"
To take the thread's question as it is, I'll respond with that generic rhetorical question. But if I were asked by what I assume (but I don't really know) the original poster's intentions were, then I'd say that some of the new Pokémon don't look like they came from the first four generations.