How similar our situation is...other than abandoning PC

?!?!?!
I just ordered 512MB from Crucial as well and it will be here within the next 2 hours....but to get to your question.
I am new to Mac and just got done reading Mac OSX books. However, I would never abandon my PC. It has its uses and if I had to decide Mac or PC, I would never choose Mac over PC for a number of reasons.
I purchased PowerBook almost a week ago to replace my portable computer, which is only 3 months old, because I need the stability and comfort on my portable and Mac serves that purpose.
If you sell your PC for parts, you won't get much money either, but if you need the money obviously it has to be the PC that has to go for you.
As for me I put too much time and effort and money into my PC to abandon it ever, and the fact that I can mess with it all I want gives me the satisfaction that I am my own master of my PC, not Steve Jobs and his goons. (or my wife, but I can't tell her that

.
If you don't use your PC too much, go ahead and sell it. If you believe that your life style will be PB centric, go ahead and sell the PC.
But if you have a lot of programs for PC and see it as your primary HOME unit and your PB as portable unit, you oughta keep both.