Yes to the last question My apologies for not making this clearer. The DEB does the same thing as the instructions on the thisweekinnuclear page, with the exception of the steps 6,7,11-13 so if you don't use it, then you can go ahead and follow all the instructions on the page Millhouse also wrote a script that automates part of the process. If you're interested, details are here

*NIX systems are a little different in that they don't allow you to run programs off of a drive that is NOT the boot drive :/ So any programs that you wish to install must be installed in the boot drive which is the reason for enlarging the boot drive by setting up the Boot from MMC.

Hmm... I'm not being very clear am i? :P Let's start over:

The N810 has 3 internal memory sections. A 128mb RAM chip, a 256mb flash chip, and a 2gb flash chip. The 256mb flash is where the original OS is located. This process outlined in the tutorial page copies the OS onto a partition on the 2gb card. The 2gb card gets partitioned into two sections. the FAT32 section is what shows up in the File Manager as "Internal Memory Card" and is what is utilized for swap memory (you should almost always use a full 128mb swap, IMHO) the Linux-83 partition is where your OS and all your installed applications are located, including KDE.

The reason this is lumped with the KDE install instructions is KDE is >300mb in size and so will obviously not fit in the standard 256mb flash chip.

Once this is all completed, when you turn on your tablet you'll get a "Select Boot Device" screen similar to the one you encounter when booting windows while pressing F12. If you want to boot to the 2gb card, then select "Boot from Internal MMC P2" or something similar. The "Boot From Internal Flash" option boots from the original 256mb card. One advantage of this is that the internal flash (the original OS) doesn't get touched on a day-to-day basis and so if you somehow brick your MMC-installed OS (like I did a few days back :/) You can boot into the flash partition and try and fix it

So... in a very long answer to your question, Yes this is similar to creating a D:\ drive but not entirely the same. It's more equivalent to taking everything on your C:\ drive and moving it to a larger hard drive that you've installed in your computer's second slot

And finally, when you clone your OS to the partition on the 2gb card, EVERYTHING you have installed on your OS so far gets copied over, so maps and all the other installed applications are automagically available. One side note on the maps. Obviously partitioning the Internal Memory Card erases everything on it so the maps that come pre-loaded with the device are erased. This isn't a big deal however because most people use MaemoMapper instead of the pre-loaded Map program. MaemoMapper has the ability to get maps from Google Maps, Yahoo Maps, OpenStreet maps and a few other map sites I've never even heard of :P

Anyway, I hope this helps and good luck!!