Although Øredev as per usual will be the place to be, in this case November 4-8, Microsoft currently run two conferences of their own, TechEd Europe and more importantly //BUILD/ which covers the latest news about the preview versions of Windows 8.1 “Blue” and releated developer tools, Visual Studio 2013 and .NET Framework 4.51.

In general for Windows users, the most important things are the ressurection of the Start Button, which, in combination with the ability to set your desktop background as being the background of the start screen as well, will give you a smoother more vintage Windows feel. Also, there are impressive new features for Multi Monitor support, such as the ability to have different DPI on different monitors, which again pushes Wndows ahead of OSX.

But for developers, in the words of Lou Reed,  What’s good?  The cool things that have emerged are that XAML under Windows 8 has evolved far further. A whole new set of controls have been released that allow for better performance when dealing with large sets of data, there are tests to measure power consumption of an app to help developers save their users’ battery Life, you can manage separate frames on separate monitors (Think Powerpoint presentation vs Speaker Notes or Point of Sales cashier view vs customer view).
http://channel9.msdn.com/Events/Build/2013/2-164

Also ASP.NET has taken a huge leap forward with the separation between ASP.NET WebForms, ASP.NET MVC, ASP.NET WebApi and SignalR have been erased, allowing you to create one ASP.NET project after which you cherry pick the features you need. This has also meant a vast improvement in what you can do in WebForms, in terms of async support and model binding to name but a few things. I truly Believe users stuck in Legacy Hell will appreciate this the most of all the things that were introduced during build, including the debugging support for Async.
http://channel9.msdn.com/Events/Build/2013/2-546

Oh. and this is only after day 2, so there’s a whole last day to check out.