Missing an iconv library makes it currently impossible for e.g. msxml3 to function properly. Tests hang or crash, and anything using it directly or would reasonably experience the same behavior.
There are a couple of different solution to this:
1. Modify wine code, possibly quite heavily, to use native Win32 functionality.
2. Import an iconv library into lib/3rdparty (or perhaps better yet, dll/3rdparty).
3. something else.
1. Would probably create a maintenance nightmare in trying to synch with wine. It would also be time consuming, create code-duplication and so on.
2. Would be very quick, require no changes to wine code (f.ex. msxml3), would only affect the code actually using iconv, and this for a very small cost in terms of memory footprint/usage. Additionally, it would give ROS an advantage over Windows when it comes to porting other free software to it - ReactOS would already have an iconv library available!
For 2, Amine found a Win32-native iconv port (win_iconv) but it needs discussion (whether) to add it to svn.