Objective-C isn't anything new. It's the language that was chosen for NeXT, and when NeXT was bought by Apple to serve as the springboard for OS X it became the de facto language for Mac OS development. It seems natural that it would also serve as the basis for iPhone development.
Actually Objective-C isn't a new language, it is really old one and it is the primary language used to develop Mac and iOS application.
The syntax isn't complex, it is Smalltalk's syntax, a little bit weird but digestible.
If you know Java you will absorb Obj-C in no time.
C and C++ are used mainly by iOS game developers.