Clearly, I can't day-dream accurately without coffee. The whole train of fantasy was kicked off by my frustration with Mail.app using proprietary storage instead of standard mboxes, and the resulting annoyance of having to use Thunderbird to feel "safe" after The OS X Defectors freaked me out.
Here's a couple of things I'd like to see in open source Apple-land:
Establish the standard package management framework for OS X. While managing and installing user apps is generally easy (copy an icon, delete an icon), when it comes to developer and more *nix-y things, it's not so good. For example, I've installed fink, darwin ports, MySQL, rails, emacs, and numerous other things. I really have no idea how to uninstall them; nor have I really dug around that much to find out. Steve has written up plenty of posts on why package management is a must for any operating system. And, as Tim Bray put it: "apt-get is just so unreasonably fucking great."
As my aside about switching to ThunderBird indicates, I'm concerned about the closed nature of Mail.app. Open sourcing it would be fantastic, but at the very least I'd like it use standard mboxes to assuage my fears of loosing my piles of email in a roach motel. Truth be told, after using ThunderBird for about two weeks, I'd much rather use Mail.app. I'd switch back in a heart-beat if I knew I had the freedom to leave. As it stands, I'm gunning for ThunderBird to catch up with the usability and native OS X integration (like with AddressBook.app) of Mail.app.
Open up the "back end" of many Apple apps, .Mac. I'd like use many of the .Mac features on my own hosted system or someone else's. The thing is, I want to use the features that .Mac has, but I don't want to pay for yet another service. Instead, I'd like to just host it, or parts of it, myself on my TextDrive or other hosting account.
To be blunt, I don't "get" why Apple has Safari instead of just working with and supporting FireFox. I'm not being dismissive of the Safari team's efforts, but as a user and developer, I would much rather there be less browsers than more. Safari is quite beautiful, it's true...but I feel like the greater good for the community would be merging those efforts into FireFox instead of forking The Browser on OS X into Safari and FireFox.
As Steve and I mention in this week's RedMonk Radio podcast(s), open sourcing hardware drivers is beneficial to the Linux community. While Apple might scoff at the idea of making it easier to run something other than OS X on Apple hardware, my feel is: hey, you're still selling the hardware...better than giving up the Cadillac-laptop category to Lenovo.
A disclaimer to all of this is that I'm embarrassingly uninformed on Apple's open source efforts and reputation...wouldn't it be nice if Apple helped us out a bit with regular briefings ;> The fellas over at The Linux Action Podcast have a much better handle on the background for all this, including the WTF-fact that you can't runthe kernel.