Will you be keeping your iPhone 4 as a personal phone and your work phone for strictly work purposes? If so, I'd get an Android or Windows phone because it seems somewhat pointless to have two iPhones. Plus, then you'd have the best of iOS and the best of Android/WP7.
I have a Atrix and these are the good things that your wife will get with it. AWESOME social networking intergration Great widgets No too much bloat wear Smaller qHD Screen Finger Scanner Loud Speakers Nice keyboard Webtop (needs LapDock or Root for over HDMI) Entertainment Center (Need TV with HDMI) 16gb Storage these are some of the bad things Bad benchmark scores due to Motoblur Junky launcher Blue notification drawer Harder to root Not much development
I have a Atrix and these are the good things that your wife will get with it. AWESOME social networking intergration Great widgets No too much bloat wear Smaller qHD Screen Finger Scanner Loud Speakers Nice keyboard Webtop (needs LapDock or Root for over HDMI) Entertainment Center (Need TV with HDMI) 16gb Storage these are some of the bad things Bad benchmark scores due to Motoblur Junky launcher Blue notification drawer Harder to root Not much development