Mind if I pull up a chair?
I'm a soon-to-be switcher, currently using a Dell Dimension 9150 with a dual-core 2.8 GHz Pentium D, 2.5 GB RAM, 300 GB hard drive, 19" Dell LCD display and running Windows XP Pro. I'm looking forward to throwing it all out the window* and buying my first Mac on or shortly after November 15th. (I get a paycheck that day which, in addition to my savings, will allow the purchase of a new Mac.)
Right now I'm on the fence between buying the 24" 2.8 GHz iMac, or the quad-core 2.66 GHz Mac Pro. The iMac looks cool as hell and is more affordable, but the Mac Pro has more muscle and more flexibility. The upcoming changes to the Mac Pro lineup, whatever they are, might make my decision easier.
* or at least selling it on craigslist