Ok here's my rant. (Codenamewinger, if you are a dev of this, please don't take it personally).
MS is almost universally idiotic about using screen real estate. (MS Office for Mac being the notable exception.) Windows is the worse about it, but these MSN screens reveal the same poor design.
Here's an example... In a normal, default windows setup browsing the internet, you have space being stolen by the Start Menu and status bar at the bottom. Then at the top, you have a huge blue bar at the top of the program window, followed by the file, edit menus...., then those freaking huge buttons that look like they go to a children's playset, then under that a links bar and if you're unlucky also a yahoo or google bar (or both) undernearth that. After all is said and done, you can only look at a web page with about 65-70% of the vertical screen space on an average monitor. (varies depending on screen resolution, admitted). With OS X you start at about 80% and only increase depending on how you have your dock configured. (I've gotten the ruler out and tried it before.)
Now just take a look at the MSN window above. The icons at the top are huge, way bigger than they need to be. The grey bar separating the two text areas takes up way too much space to be used for only two buttons. And, like I said earlier, that huge send button just screams "I'm a waste of screen space!!!"
Ok, I think I'm done. End Rant...