According to Islam, or at least the view of Ahlul Sunnah (Sunni's), those who have not heard the Message, will be judged too, and can indeed be thrown in 'Hell'. There is no guarantee that they will automatically enter 'Paradise'.
Judged for what?
Not worshipping God as he demands?
or not behaving nicely?
In that case God does not need to send the Quran does he?
He can judge them on their merit as good person or not
and not following Islam.
And does not have to bother with sending prophets etc... what a complete waste of time that was. It only caused confusion! ;-)