Hmm, I usually have 8~10 desktops at all times. Use for work since I work at home, coding-application design, testing new OS/Apps, if friends drop by for some gaming, et al. Plus usually 1 or 2 dual socket workstations for my video/3d modeling work. 6 physical servers atm, 10g network, iSCSI 24TB SAN, 250mb Fiber Optic Internet. Usual business at home setup...
I work on a 12~18 month cycle for most of my PCs, been that way for years. Got 2600k at release. And AMD FX was not a very compelling alternative. Bought FX-8150 and replaced with 2500k within 30 days. Got 3930k at realease and then 3820 to replace i7-950. So, out with i7-975x and i7-875k, nice to get rid of oder equipment. Still working, but would like more computing power if I need it. Last unit will be a i7-990x that will go once IB-E or Haswell has been released.
Same with Video Cards, just got 4 680 GTX to replace 580 GTX 3gb. Running a few 7970s also. Just waiting on either 7990/690 to replace some more video cards as I can.
Laptops are replaced when better models are available, waiting on 675M/7970M with IB laptops, will order 2 at least. Maybe a 3rd sometime in Aug/Sep...
Off topic..you have some amazing hardware in your house.I hope you also invest in some reliable alarm system ..or own some guns