Considerations and Pitfalls of Wi-Fi Direct
Some people say that Wi-Fi Direct provides the same range as regular Wi-Fi; however, this isn't completely true. The client devices themselves will likely have the same transmit power and reach. But there's no wireless router or AP. The overall range of a Wi-Fi Direct network can be much less than traditional Wi-Fi networks, depending upon the placement of the Wi-Fi Direct devices. A wireless router or AP can be placed in a central spot, relaying each client's communications. Wi-Fi Direct networks don't have this.
Though the Wi-Fi Alliance says it is including enterprise management features and that Wi-Fi Direct will be in another security domain, it will likely still create a new security hole in your network.
It isn't clear yet how Wi-Fi Direct will work exactly, but it is very likely that network administrators won't be able to completely control the Wi-Fi Direct feature of their wireless clients. This means a user might be able to knowingly or unknowingly create a Wi-Fi Direct network on their computers and devices, which might open up unauthorized access to that particular device or the entire network.
The Wi-Fi Alliance also says that Wi-Fi Direct will be compatible with existing Wi-Fi gear, even without any software upgrades. However, they should include some fine print here, too.
Given the proposed features of Wi-Fi Direct, devices that aren't upgraded will likely only have basic functionality. This might mean, for example, that only upgraded devices can create or manage Wi-Fi Direct networks. Additionally, it may mean that only upgraded devices will have the enhanced discovery and management features.