I am also very interested in FSX, and I can tell you that many other people are in the same boat as you. The minimum requirements defined by m$oft for FSX are a joke. I am currently building a new home system for my business, which I also use for gaming, and these are the specs I am looking at. I expect them to run FSX on medium to high settings, if I'm lucky.
Intel® Core 2 Extreme X6800 2.93GHz
NVIDIA nForce 680i SLI Motherboard
2GB DDR2 Performance SDRAM at 800MHz
2 x 250GB Serial ATA 3Gb/s 7,200 RPM on RAID 0
18x Dual Layer DVD±R/W Drive
768MB NVIDIA® GeForce 8800 GTX
If you want to discuss this with other people who are playing the game with a variety of PC configurations, I suggest checking out http://flyawaysimulation.com.