tl;dr important stuff all works. Minor stuff like finger print scanner easily fixable
The hardware is 'certified' by Canonical but this is meaningless because it doesn't say what of the many options Dell offer for the E5430 was used. It also doesn't list correct details for hardware such as Bluetooth, or even that the finger print scanner exists. And there is no way to submit fixes. And the contact us page is 404 compliant. So let's hope Google finds this for you instead :-)
And of course Dell wont tell you any of this, let alone sell you a system with no Microsoft tax, even though the official data sheet lists Linux as an option.
On a fresh install of Kbuntu 12.04 all the important stuff like 3D graphics, HDMI out (with audio), sleep (no real need to enable hibernate support when you have an SSD and over 6 hours of battery life). Also the camera, microphone, WIFI and so on works out of the box along with Bluetooth too. I've not even looked to see who really makes those various bits!
My hardware has the Intel wireless option, but not the A-GPS / mobile options; my phone can turn into a WIFI access point if needs be so I can't speak to how well they work. Not the CPU should matter, but it's one of the Intel i5 versions.
Hot keys (fn+cursors) for the keyboard back light and screen brightness work too; as does fn+function keys for controlling playback in Amarok.
SSD
I sprung for an SSD, as I now think everyone should - at least for the O/S partitions. Even though I picked EXT4 for the partitions, the install didn't notice it was an SSD, so didn't enable TRIM support. And for reasons known only to the gods, Ubuntu still doesn't use a RAM disk for /tmp - and making pointless writes to SSDs greatly reduces the life span.
So I had to add the discard mount option and enable tmpfs by hand:
tmpfs /tmp tmpfs defaults,noatime,mode=1777 0 0
tmpfs /var/log tmpfs defaults,noatime,mode=0755 0 0
# / was on /dev/sdaa during installation
UUID=... / ext4 defaults,discard,errors=remount-ro 0 2
I read that replacing /var/log wasn't good, but as I don't care about the logs there and can swap back if I want to investigate something, what the hell. So far this looks to work and the various directories in /var/log are recreated at boot fine.
The machine also has four gig of RAM, so I've no swap configured either; again, this would eat erase cycles on an SSD, reducing it's life, and in the unlikely event I run out of RAM I can just buy another four gig stick and the problem will go away.
Fingerprint Scanner
The fingerprint scanner is a
$ lsusb | grep AuthenTec
Bus 001 Device 006: ID 08ff:2810 AuthenTec, Inc. AES2810
install fprint_demo etc, then overwrite with libfprint from git 7eafca7babe40bc7dddd27ce9051b13b90ada021 @ Thu Jan 24 12:05:36 2013 +0300 Follow along from http://ubuntuforums.org/showthread.php?t=760018 to enrol your prints but no longer need to edit PAM by hand. I had a few problems with the print never verifying, but the folks on the libfprint mailing list were helpful - it's just a case on enrolling as high a quality scan, of as much of your finger as you can. There is a knack to swiping across the scanner at the right speed you need to get into your muscle memory :-)
Need password and print to login and unlock not either/or. Sudo asks for print, falls back to password which is right. KDE password prompts only take password, accept the screen saver which needs both.
Touchpad
touchpad works, but only as mouse. via https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1090833 from http://dahetral.com/public-download/psmouse-alps-dst-1.2.tbz/view now get full three finger mutitouch, edge scroll etc
Bluetooth
Wouldn't work in KDE after resume. hcitool still shows it. Workaround : https://bugs.launchpad.net/ubuntu/+source/bluez/+bug/818243/comments/8
KDE
battery time left - KDE folks are idiots - https://bugs.kde.org/show_bug.cgi?id=304510. Install Enhanced Battery Monitor applet, patch as per http://kde-apps.org/content/show.php?content=153981
Default is a giant flashing white light in your eye all the time WIFI is on. Make it steady when WIFI on, off when WIFI is off (obvious UX!)
$ cat /etc/modprobe.d/wlan.conf
options iwlwifi led_mode=1
TBC
Thank you so much!