It is no doubt that almost every language has differences in its written and spoken form. But I think Indonesian has so many differences in these two forms. And it is even worse when I see the wikipedia page about Indonesia, It is mentioned that apart from Indonesian, there is a spoken language named slang. And when I open the page about slang. It is spoken Indonesian, or slang language of Indonesian. I think wikipedia treated the slang language of Indonesian as separate language of our standard Indonesian. As a native speaker of Indonesian, I never felt felt that these two languages is different. I speak Indonesian everyday, but in spoken form. I just speak standard form of Indonesian when I was in formal situation and of course when I wrote any articles. And of course I know that there is none Indonesian speak in standard Indonesian in informal situation, even the president. When I try using some standard Indonesian words to my friends, they laughed me, and say to me "you were speaking like a book". As a native we know that, these two forms are quite differences in structure and diction. I think even Indonesian itself, will trying quite hard to speak standard formal Indonesian. The'll need time to think the diction and structure of the sentences. 

My question is,  is it good or bad that Indonesian standard written form really different from the spoken form? and is there any other languages which has more differences in standard and spoken form? I just wonder, if the spoken form may be will become a separate language in the future apart from the standard Indonesian, like the Indonesian be the separate language apart from local malay and Malaysian standard malay.