This is good news. Most of the features are interesting. One thing I want to ask is why the WPF designer is supposed to have the same feel as the WinForms designer when it's time to drag and drop a control? This is so annoying when you want an autosizable control.

My wish list:

1) Remove the default property value set by the designer when you drag and drop on the designer surface. Make use of the existing panel. I don't find it productive to drag and drop into the xaml surface to have no property set. This is WPF and the designer should be WPF oriented.
2) Add a filter button in the property editor and show only the property that have been set and modified in the designer.
3) Add in-place designer for menu.
4) Add a button in the designer to set the design time only binding for the DataContext for better discoverability.
5) Localization of the UI inside cider. Think extensibility here, localization could be stored in database, in resources files, or elsewhere.
6) Could be interesting to have a view to show the invalid control binding according to the design time DataContext. This could also appear in the warning / information list produced at compile time.