I don't need no technical paper to know how much memory I need... the more the better. imo.
4GB minimum, 8 GB recommended is my opinion. 8 GB cost you $ 110. so why are people still analyzing how much they need, and if 1 Gb or 2 GB are enough? Most better laptops come with 4GB already.
If cost really was an issue I could understand the penny-pinching and analyzing. I consider an SSD and really want to have just enough because each GB costs me much money. With an HDD I don't even think about size anymore. The same with RAM.
Windows 7 (and vista for that matter) need more RAM than XP, but also use it much better. The more they have the more they can use to speed up your daily life.
The only limit to RAM (imo) is that 2 GB modules are cheap, 4 GB modules very expensive) So my motherboard is the limit (with 4 slots and cheap 2 GB RAM I'm limited to 8 GB etc.).
At work I used to have 1 GB and the PC crashed all the time with autoCAD. Once my 3 years were over (IT replaces them every 3 years) I got one with 4 GB (after harassing them since their standard PC configuration only increased to 2 GB). with the time I wasted with a slow and crashing PC and being frustrated, with that value (incl. overtime pay, tax etc.) they could have bought me the biggest gaming rig in the universe.
I'm sure our IT guys are exactly the people who read those papers and "optimize" the PC to our needs (and needs in the next 3 years). So they saved $ 20 per PC, great.