With the latest update v3.5.9 I get the following errors when compiling for Windows Store using SDK 8.0.
Assets\NGUI\Scripts\Internal\ByteReader.cs(31,19): error CS0103: The name 'File' does not exist in the current context
Assets\NGUI\Scripts\Internal\DataNode.cs(724,12): error CS1061: 'System.Type' does not contain a definition for 'IsAssignableFrom' and no extension method 'IsAssignableFrom' accepting a first argument of type 'System.Type' could be found (are you missing a using directive or an assembly reference?)
Assets\NGUI\Scripts\Internal\DataNode.cs(727,12): error CS1061: 'System.Type' does not contain a definition for 'IsEnum' and no extension method 'IsEnum' accepting a first argument of type 'System.Type' could be found (are you missing a using directive or an assembly reference?)
The first error I'm pretty sure was not there on earlier versions.