You can use your Surface as a remote control for a PowerPoint that is running on your laptop. That's not quite the totally wireless Surface--->projector that you were hoping for, but from past experience, most wireless video transmitters can be a bit iffy when it comes to signal reliability because a lot of them require a constant line of sight between the transmitter and the receiver. All it takes is for your body to get between the Surface and the receiver unit, and the wireless video connection can drop out. (Had this happen to me several times.)
If you don't mind lugging your laptop and Surface to give presentations, there is an app for the Surface called RemotePresenterView that lets you wirelessly control the presentation running on your laptop. It supports inking with an annotation pen, and it has a laser pointer, slide sorter, notes view, etc. Basically, everything you'd get with PowerPoint's actual Presenter View, but touch optimized and wireless. It supports connecting over WiFi, and can create a private WiFi hotspot on your laptop to use if there is no WiFi available where you're giving your presentation.
Here's a link:
RemotePresenterView app for Windows in the Windows Store
There's also a limited-functionality free version:
RemotePresenterView Free app for Windows in the Windows Store
If you don't mind lugging your laptop and Surface to give presentations, there is an app for the Surface called RemotePresenterView that lets you wirelessly control the presentation running on your laptop. It supports inking with an annotation pen, and it has a laser pointer, slide sorter, notes view, etc. Basically, everything you'd get with PowerPoint's actual Presenter View, but touch optimized and wireless. It supports connecting over WiFi, and can create a private WiFi hotspot on your laptop to use if there is no WiFi available where you're giving your presentation.
Here's a link:
RemotePresenterView app for Windows in the Windows Store
There's also a limited-functionality free version:
RemotePresenterView Free app for Windows in the Windows Store