when Isa (AS) will come, Muslims who will NOT believe him will at that time be also a 'muslim ummah'. Because whoever will start believing in him will be considered non-muslim.
So really, if you think about it .. this Muslim Ummah that you and coolguylin keep talking about will always be there, who will be declaring anyone not agreeing with their beliefs as 'non-muslims'
Then stop blaming Pakistani parliament, they did not do anything new.
The same goes to you, anyone not agreeing with you, you consider him non-muslim. There are many people who have claimed to be Mahdi or messenger, it does not mean, they shud be recognized as muslims.