Everybody has an Idea, but no one will ever suggest you to do something with that domain that is anywhere close to a matrimonial site or something in those lines.
It is a bad practice to even talk about it.
Taking that out of context, you can do a predictions and horoscope site for the Islamic World. The definition of inchallah(Insha'Allah) from wikipedia is "Insha'Allah (Arabic: إن شاء الله) is an Arabic term to indicate hope for an aforementioned event to occur in the future" I think it will be in context and relevant.
Good Luck,
Nanda.