The special theme for the February issue of MSDN magazine is Dynamic Programming - which is still a hot topic.
In Understanding the Dynamic Keyword in C# 4 Alexandra Rusina provides a general overview of the new dynamic features in C# 4 and with some more in-depth information about how they work with other language and framework features, such as reflection or implicitly typed variables. The article has references to further reading but if you want a introduction see Dynamic C# 4.
Continuing the dynamic theme Ambar Ray has an article categorised as Dynamic Data, Pattern Matching Database Records with F# in which he shows shows four different matching algorithms and the F# code to implement them. It starts with the instruction Download the Code Sample so expect a practical experience.
The next item to catch my eye was Juval Lowy's Known Types and the Generic Resolver - about the "hassles of data contract inheritance" in WCF.
Charles Petzold devotes his regular UI Frontiers column to Sound Recording in Windows Phone 7 and Terrence Dorsey's Toolbox is also Windows Phone 7 - a selection of developer resources.
Visit MSDN Magazine for details of the other articles and columns.
For details of previous issues see:
MSDN Magazine - to read online or offline
Also checkout the new pivot menu user interface -
I think it's terrible!