Missing from the iWork suite: drawing, painting, and database applications.
And there are plenty of features that could be added to Pages (indices, cross-references, figure captions and numbering are feature I could use) and Numbers (solver, statistical functions, better charts).
Not sure what they could do with iWeb. It's a closed program that won't edit existing sites, and won't tolerate hand editing of the html. I looked at it for a couple of minutes and then ignored it. And iDVD, well DVDs are so last decade!