b would make me shelve permanently any dreams i may have of one day affording a macintosh, d would make me consider buying staroffice instead, because i can't stand all this desktop integration crap (yes, yes i know, but let's not get into it).
and a and f would be very good, and would definitely be a little nudge to a lot of people who i know who don't use linux already.
i'd like to see apple release quicktime (possibly using Qt?) for linux. It could be called QtQT!
of course, they've missed the boat what with mplayer and all, but it would be significant to windoids.
and your comments about gimp are spot on. although gimp is great in my opinion, i get the feeling that all those people who say it's not as developed as photoshop are just pissed off about the user interface. get over it i say, but if they need some smooth GUI and somebody wants to put in the time then go for it i say.