Recent advances in wireless communications technology and car industry made it possible to consider wireless Ad-hoc (or mixed Ad-hoc/infrastructure) networks, providing connectivity among vehicles on the road. Such network, often referred to as VANET (Vehicular Ad-hoc Network) is seen to be one of the most valuable concept for improving efficiency and safety of the future transportations, as well as boosting operators' revenue. Thus, several ongoing research projects supported by industry, governments and academia, establishing standards for VANET networks. This paper covers current research challenges and future applications for such networks, discusses possible deployment scenarios and provides some insights to the state-of-the-art of the current standardization of interfaces and protocols on a global scale.