Since I want to play with accelerated OpenGL, this is where I expected trouble, with having to download separate binary-only drivers and what not. But to my surprise, I just started up X11, and had working DRI before even trying.
This is how it should work, and how it does work with FreeBSD and Xorg.
Sound and removable media
The sound driver didn't load by default, but adding the line
snd_ich_load="YES" to the file
/boot/loader.conf took care of that.
Playing and reading audio and data CD:s just works, as well as playing DVD movies (using xine).
Mounting my umass mp3 player also just works, but to allow myself
to mount it as myself (rather than having to su), I add
vfs.usermount=1 to /etc/sysctl.conf.
To make the mounting more convenient, so I just have to type
mount /mnt/pod rather than a full set of options, I
also add a line to /etc/fstab:
/dev/da0s1 /mnt/pod msdos rw,noauto 0 0
noauto option! Since the drive needs to be
explicitly unmounted before I remove it, I don't want it to mount itself
automatically at any time.
ACPI / Battery status
The ACPI reporting of battery status also just works, as well as the gnome panel applet for reporting it. There is also an applet for lowering CPU frequency (for longer battery time) that just works.