Windows 7's native Virtual Wi-Fi sounds complicated—it virtualizes your wireless adapater into as many wireless adapters as you want—but making your machine think it has more than one wireless adapter is pretty useful:
With multiple independent wireless connections—the virtualization software turns your single hardware wireless connection into several—you can tap more than one hotspot simultaneously. Or probably more useful, it's easier to set up a mesh network, where every system in the network acts as a repeater—one "adapter" grabs a signal, another passes it on. In Windows 7, you're limited to one virtual adapter, but that's all you need to easily share a Wi-Fi connection with other computers.
You can't do it yet in Windows 7 RC1 or the beta because the drivers for wireless adapters to make this happen don't exist yet, but they will, so you'll see it by the final release for sure. Pretty useful, though I wish they'd make Network and Sharing a little easier still to navigate around. Maybe that's too much to ask. [I Started Something via Engadget]