In the past few week I’ve used most of my development time developing Windows Phone 7 applications. Here’s a warning for those who are using MVVMLight: Its EventToCommand-feature is leaking memory. So, if you have for example a ListBox, don’t use EventToCommand to bind any functions to the items. Using WeakReference doesn’t help.
Here’s couple screenshots from one application where a listbox contains around 800 objects and every object is touchable. When using MVVMLight the memory usage looks like this after a while:
And here’s a picture where MVVMLight is replaced by using code behind event handlers:
Here’s couple related issue reports from the Codeplex:
Except for this issue, I really like the library.