What is the File Structure in Haiku, and how are programs going to be installed?
I hope Haiku does not have the UNIX styled file structure with lots of folders in root etc.
You can try out a VMWare image and see for yourself. 
File structure is somewhat similar to Unix/Linux but with less folders ( half of Linux’s folders ) and better organized - so not that bad.
It is a little more complex than Windows but not as crazy as Unix. And easier to learn and understand.
Many current programs are provided as Zips. You unzip, copy program ( and any libraries ) to the right folder(s) and create a menu and/or desktop link. People can also create a package ( similar to Linux rpm file ) which will make the install automatic and make it easier to uninstall with two clicks.
IMHO, BeOS/Haiku file structure is the most logical and easist to administer from all the platforms I’ve seen. As the above poster has mentioned, fire up the Haiku image (VMWare, QEMU, VirtualBox, Parallels, whatever) and have a look. It’s not like *nix, but there is a POSIX compatibility layer which adds some *nix metaphors.
Even though it’s better organised than other systems, one thing I’d like to see improved is the removal of the driver/symlink relationship in addons/drivers. To make the kernel simpler during boot up, it processes all drivers in the bin directory, while there is a dev type hierarchical relationship in the dev directory, used for mananging the /dev drive. Why cant the kernel scan the dev directory, and ditch the bin directory (ie. remove the symlinks)?
There is still room for improvement, but that belongs on the glass elevator mailing list.
Cheers.