The evolution of industrial networks can be summarized as a constant battle to define the universal technology that integrates field devices and applications. Since the Fieldbus wars in the 1980s, diverse wired solutions have been proposed. However, this scenario has been changing due to the introduction of industrial wireless sensor networks. In the last 10 years, the development of deterministic scheduling techniques, redundant routing algorithms, and energy saving issues has brought wireless sensor networks into the industrial domain. This new communication paradigm is governed by a de facto standard, the IEEE 802.15.4, and more recently also by the IEEE 802.15.5. However, there are signs of a new battle on the horizon with the new publicly available specifications of WirelessHART, ISA100.11a, and IEC 62601. In this chapter, to the authors analyze the advantages and drawbacks of these emerging technologies for industrial wireless sensor networks.