From Fedora Project Wiki
A few thoughts:
* The Codec installer dialog: * looks a bit broken: why the "Windows Media Video 9 decoder" listed twice? * The entire explanatory text can be simplified to: "You need the 'Windows Media Video 9 decoder' plugin to play this content." * The unknown file dialog: * the red sign which suggests an error. I think this is inconsistent with the rest of the dialogs which show a less threatening icon * I think we can use the PackageKit icon instead, no? * the full path of the file is irrelevant in this content, I think we should display the name+ext only * The font installer dialog: * Missing period at then of explanation * The name of the font should be mentioned: "The 'Arial Black' font is required to view this file correctly." * Sometimes we use "No/Yes" for buttons, sometimes "Cancel/Search". Since you're asking the question, I think "No/Yes" is more appropriate.
As a bonus would be nice if we could automagically search and display the options right there instead of asking the user to search.