Wow. I've got some serious 'puter envy That's a monster of a laptop!
While nowhere near as beefy as your setup, I'm cutting at this very moment with a fairly similar configuration on my T500. I've cut everything from DV to DVCPROHD to XDCAM-EX with it, and mine only has a P8400 with 4GB of RAM. I've got a 320GB/7200RPM Hitachi in the UltraBay, and that serves as my media drive. While I have on a couple of occasions stored my project folders on the system drive, I've found it's just easier to save it all on the media drive; I just do regular backups of my project files and content like PSD files and the like. All my media is originally offloaded to external drives and archived there, so even if the media drive burns out, I'm usually not out too much. I do very little rendering of previews on the laptop--I'll usually rough cut and sometimes even final edit on the laptop, and then move to my workstation for color correction or effects or what-not--so it doesn't bother me much to render to the same drive. If I do exports, I either hook up an external USB drive or similar, or I export to my system drive; seems to move pretty quickly.
If this is your one-and-only workstation, you'll probably want to look at some sort of external drive or array, connected through something like FW800 or (even better) eSATA (you'll need ExpressCard adapters for these connections). But if you're just looking for editing-on-the go, this basic layout will work.
with a Samsung 256Gb MLC SSD (with 3 partitions, one of which contains the OS) set up as the primary disk & a Seagate 200Gb 7200rpm running in the Ultrabay of the laptop
What is the purpose of the partitions? I can think of no reason to do that, and no way that it will help with your NLE laptop.
That was one reason that I went with the Sager - I could get 3x physical 200GB 7200RPM SATA II's back then. Now, it would probably be 3x 500GB's. Physical HDD's are the way to go, even on a laptop.