And there’s nothing as terrifying for those same developers as waiting to see if those new features do similar things to the software they’re already selling.
We all know what happened to Watson and Konfabulator, and countless others. They get gulped up into Mac OS X. This year's great shareware that just got a lot more useless include: SuperDuper, ChatFX, VirtualDesktop Pro, Quicksilver, Pulp Fiction, Mail2iCalToDo, Searchlight, and others I am not familiar with.
There are some other good articles on this same subject, Apple’s Research & Rip-off department and 7 Apps on Leopard’s Hit List.
On one hand, this shareware gets expensive, and they usually conflict with each other or the operating system. When Apple incorporates this software into OS X, it works as it should, usually better with more features than the shareware, and it is one price, not 15 different shareware bills.
It also forces shareware developers to one-up Apple when a feature from their shareware gets eaten by Apple. This is good for the community, very good.
The other side of course is that a loyal Apple shareware developer is out a substantial source of income. It sucks, but you know what? That is how products progress. In any industry.
I just hope that Path Finder doesn't get eaten by Apple. Sadly, I have been waiting for it to happen though.