I've got my Raspberry Pi 2 this week and promptly downloaded the Windows 10 IoT core for it.
Scott Hanselman's blog post covers most of what you need to get started
http://www.hanselman.com/blog/SettingUpWindows10ForIoTOnYourRaspberryPi2.aspx
I've summarised the bits that I either didn't read properly or had to go searching for :-)
Download the Windows 10 IoT core and follow the instructions here: http://ms-iot.github.io/content/win10/SetupRPI.htm
In the zip file that is downloaded there is also an MSI file. Install this on your dev machine and you will get an IoT Watcher application that shows all devices on your network. It shows you all the details you need to remote debug your IoT Core device. If you right click on the device you can copy the ip address. This was really useful for this because the only display I could connect my Pi to was my TV (Mainly due to having the wrong cables or no hdmi port on my monitors). Although it was quite impressive to see such a small device on a big screen, it wasn't very practical, plus I keep getting kicked off as the family want to use it to actually watch TV! I'm going to get myself a cheap small monitor just for my Pi. The IoT Watcher application allowed me to check that the Pi was running and also to get its IP address
In order to configure your device including changing the password and setting the machine name the following commands are useful
http://ms-iot.github.io/content/win10/samples/PowerShell.htm
To get started developing for your device download the samples from here: https://github.com/ms-iot/samples
I started with the Blinky sample and this can be the basis for your applications, I picked this one as it shows how to use the GPIO to control something. When this is loaded in Visual Studio 2015 the MainPage.Xaml.cs file is where all the work is done. InitGPIO() sets up the pins for connecting the LED to and there is a timer that ticks to turn the LED on and off
Debugging the application can be done directly on the device and this needs configuring. In order for this to deploy you need to ensure that authentication is turned off in VS as won’t deploy otherwise. When setting the device in VS, I could not get the device to appear in the search tool so I manually configured it with its IP address. This can be done (or to change the device) in the debug section of project properties. Once deployed you can set break points in the code which is running on the device and debug it remotely.
Now I've got that working I've dusted off my soldering iron and the rest of my electronics kit and I am off to play. More later.