> I'm contemplating buying a new Dell 4600 desktop, to run under current.
> Hmm...  Of course, I don't know just controller they're using;

 I have two 4600's, about a month old.  I went with plain IDE, but I can see
SATA sockets on the motherboard, and it's mentioned in the BIOS.  Here's how
the controller and my devices show up:

piixide0 at pci0 dev 31 function 1
piixide0: Intel 82801EB IDE Controller (ICH5) (rev. 0x02)
piixide0: bus-master DMA support present
piixide0: primary channel wired to compatibility mode
piixide0: primary channel interrupting at irq 14
atabus0 at piixide0 channel 0
piixide0: secondary channel wired to compatibility mode
piixide0: secondary channel interrupting at irq 15
atabus1 at piixide0 channel 1
piixide1 at pci0 dev 31 function 2
piixide1: Intel 82801EB Serial ATA Controller (rev. 0x02)
piixide1: bus-master DMA support present
piixide1: primary channel configured to native-PCI mode
piixide1: using irq 9 for native-PCI interrupt
atabus2 at piixide1 channel 0
piixide1: secondary channel configured to native-PCI mode
atabus3 at piixide1 channel 1
wd0 at atabus0 drive 0: <ST3160023A>
wd0: 32-bit data port
wd1 at atabus0 drive 1: <ST380011A>
wd1: 32-bit data port
wd0(piixide0:0:0): using PIO mode 4, Ultra-DMA mode 5 (Ultra/100) (using DMA data transfers)
wd1(piixide0:0:1): using PIO mode 4, Ultra-DMA mode 5 (Ultra/100) (using DMA data transfers)
atapibus0 at atabus1: 2 targets
cd0 at atapibus0 drive 0: <JLMS DVD-ROM XJ-HD166, , DD05> cdrom removable
cd0: 32-bit data port
cd1 at atapibus0 drive 1: <_NEC DVD+RW ND-1100A, , 10FD> cdrom removable
cd1: 32-bit data port
cd0(piixide0:1:0): using PIO mode 4, Ultra-DMA mode 2 (Ultra/33) (using DMA data transfers)
cd1(piixide0:1:1): using PIO mode 4, Ultra-DMA mode 2 (Ultra/33) (using DMA data transfers)

> For that matter, I don't know what type of GigE card they have, nor what
> "Intel Extreme Graphics controller" is and whether or not it's supported by
> XFree86.

 I went with the NVIDIA card and the 100MB card, so I can't help you there.  I
also ordered the SoundBlaster Live card, and it's not working under -current:

Creative Labs product 0x0006 (audio multimedia) at pci2 dev 2 function 0 not configured
Creative Labs product 0x7004 (miscellaneous input) at pci2 dev 2 function 1 not configured

> that sort of detail doesn't seem to be on the Dell web site.

 Their "add ons" and "upgrades" seem to change rapidly.  Quadruple check your
order every time you hit the "refresh button" to change your purchase options.
And save your printout of what you actually ordered to compare to what's on the
packing slip when it arrives.  I like my Dells, but there's something seriously
wrong with their web site.