iPhoto is about organizing photos, Photoshop Elements is about retouching photos - true they have some of the same features, but they are really different applications.
I'd be really happy to see an OS X version of Photoshop Elements - currently it is the only application I require Classic mode for. And while it generally runs fine, it sure would be nice to have it run native. The healing brush in 7 also seems like a tool esp. useful for the non-professional crowd, but then of course Elements can't have all the features of Photoshop 7.
I'd also like to see more enhancements to iPhoto - similar products like Epson Film Factory (OS 9 or Windows) provided color adjustment and auto-correction features in a non-destructive manner. An auto-correction feature was good for tweaking a large number photos without too much effort. Then if you want to do anything special, you open it with Photoshop Elements instead.
Of course with the file browser (improved in 7 over PS Elements) and TWAIN support, I could see myself using PS Elements for OS X over iPhoto all the time.
- n8