One of the designs that I'm not happy with is how i'm handling file path resolving. Right now I've got a static (re: global) delegate that is called to resolve files. This allows me to map this to a Server.MapPath in the web case, and a Path.Combine on the client. The problem is that the "map" ends up being per app domain - which works great for ASP.NET, but sucks for WinForms... At this point I'm not going to rewrite it, but I'm just not happy with the design.

Note I've created a BlogX category for tracking progress and comments on this specifically.