Could fans accept a new cast?

[Ximena Valdivia]

I was wondering about it for a long time and for instance my answer 
is like no! But that is because I'm a big Harry Potter fan, so I 
though it was sort of obvious that I was used to the trio and didn't 
want them to leave but then, last monday something happened. I 
finally manage after a year and a half to convince my big brother 
(he is 23) to see HP & SS. He saw it with his girlfriend, after that 
they spend the next 48 hours asking 400 questions about it (they 
have never read the books) then yesterday they saw HP & CoS and once 
again with the questions. Today at lunch time, they were asking me 
when the third movie was coming and while I was telling them the 
dates and that probably that one or GoF is the last one the trio is 
going to make, they saw in such a way like if I just told them that 
Xmas was cancelled, and they began to tell me all the reason why 
they (the trio) should not stop doing the movies and all those 
reason I know, but I let them talk. So, what do you think? do you 
think all of the rest of the people that watch HP will react the 
same way?...well not the same way but you got my point.

Ximena