Working on it right now - first little steps, as I have a "day job" that takes most of my time at the moment (crunch time in a software project, another 4 weeks to go).
After that i will switch back to 8 hour days, and that allows me mostly to start real trading then (which is currently totally stopped). I will spend the side time to learn trading and working on my trading setup (which incidentally may become a product - once I have the "core framework" lined up, I am possibly going to get that thing up with 1-2 programmers).
Total .NET colusion in C# (obviosuly - I am a C# guy by now), using SQL Server 2008 as data storage in the backend. Planned is a client/server architecture, so that visualization runs on my client, data and strategies run on a server in a hosting server. Multi user, with different rights.
I am not sure yet about how they will talk to each other. Naturally WCF for the "non streaming" stuff, for the rest I think of setting up WCF controlled TCP or UDP streams. This means that content setup and control is done using WCF calls, but data streams are direct and binary encoded
The visualization WILL be WPF based. I see no reason not to at the moment. Silverlight may enter in for some ASP.NET micro site, mostly to allow me to do some "emergency" control from my smart phone (stop strategies, look at P/L, close positions).
At least that is the plan. If NT7 comes out well, I may actually delay that quite some time
