There are some applications that don't exist for OS X. One of the biggest omissions is quality speech recognition, but another is maps. There's nothing on the map like Microsoft Streets and Trips, even though S&T has been getting slower and buggier over the past two to three years.
I used to miss that application, though I became accustomed to its absence. Google Maps, and Google Earth, eased my pain -- except when I was on an airplane.
Now Jeff Atwood tells me I don't need to miss Microsoft Streets and Trips any more. His head-to-head real world testing demonstrates Google Maps is substantially faster and more usable than MS&T. Not merely comparable, but absolutely better. Also free, and it runs just fine on Camino/Firefox (Safari? What's that?).
I actually don't care that much (yet) about speech recognition on my desktop, so if Jobs today introduces OS X remote control functionality even 80% as good as Windows' ancient terminal services/RDP functionality the day of the PC will have truly passed.