Well then the whole thread is pointless, its like asking "is a 3TB hard drive too much"... The answer is NO if you plan on using it all, and YES if you only plan to use 25% of it.
So what? If someone can afford it, wants it, does it, what's the big deal?
It only cost me about $235 for my 16GB of RAM in my iMac. It is well worth it to me because I know that I will probably never ever run out of RAM while working. As I am typing this, I have the following running:
Mail
Safari
iTunes
Skype
Twitter
Numbers
Pages
Toast 9 - rendering a DVD and using all 8 cores of my 2.93 i7
Out of all that, I still have 12GB RAM available which includes free and inactive RAM. I still have tons of RAM and about 50% of my CPU cycles still available to do more.
Some times this happens... But it's rare that I manage to get page-outs... usually it's because of a program acting up and leaking memory (which, on second thought, can be a bit easy given my primary line of work - a software developer ). Sometimes it's good to have that buffer of extra memory in those cases cause then you can kill it much more easily before it uses up all your memory.