SSIS brings a very cool feature with it... Expressions help you very much to dynamically change the behaviour of your package. There are already some posts about them around (i.e. search for “expressions” on Kirk’s blog http://sqljunkies.com/WebLog/knight_reign) so I don't want to talk too much about the feature itself. What I'm just thinking about (and posted on the technical forum http://forums.microsoft.com/msdn/ShowPost.aspx?PostID=74473) is a way to find out which property is affected by an expression... OK, you can just look in the list of expressions (the place where they are defined), but just imagine you get a package and you wonder about why it behaves differently from what you see on the first sight... A very simple example would be a SMPT task sending a different message than defined in it's properties. After a while you think "well, that could be an expression" and... yes, there is one defined. So why don't make thinks easier by marking properties affected by expressions i.e. with a different colour or font. That would help a lot...
I'll pass that to Microsoft, too... Perhaps someone will take care of that...
Thomas