Zoolander the original is a cult classic with all sorts of memorable characters that will be back for the next one. I heard Will Farrell doesn't have a big part as Mumbatu but that's always been a way to swerve us fans before. Like Bill Murray in Zombieland, a surprise for the audience is better.
Yes, Zoolander 2 is going to be great. The cast and story line of the first one were perfect. The dialogue and situations were hilarious and really struck a chord with most young adults in the audience. I don't know anyone who didn't like it. The cast will only be funnier the second time around.
I think that since it's a lot of the same cast members, the sequel will still be really great. I have yet to see the new trailer that they just released the other day but I know a lot of people who are already raving about how great it's going to be when it comes out soon. I'll definitely be getting tickets to see it when it comes out.
Most of the time seconds part movies are hardly ever as good as the first. Zoolander was a good movie, but not great in my opinion. The only way to make this a great movie would to be to redo the entire storyline, which I doubt they plan on doing for the second movie.