New Rig

I have been wondering if it is time to buy a new rig. I like to have close to the latest and greatest but just can't justify, in my head, the need to have the very latest. I am usually satisfied with this method as I can get a couple of years out of my purchases before the new games coming out simply won't run well on what I have. My current machine is a little over a year old. It is a Pentium 1.8 GHz machine with a NVIDIA Ti4400 video card. I haven't had any real issues running anything yet. The real problem lies in my second machine, or as it is affectionately called, "The Kids' Machine". This is the machine my kids use for whatever they are interested in and I use it as a backup for business files. This machine is a 833MHz machine. It has a TNT2 card in it. It is starting to show its age.
The first sign was Halo wouldn't run on it. When games start coming out that complain about your hardware, it is time to think about upgrading within the next 6 months or so. My dilemma is, I think it is the wrong time to upgrade my main machine. It still has plenty of punch and new machines out there just don't give enough bang for the buck. The newest Intel chip the Pentium 4 Extreme Edition looks good but it is coming out as a sort of bridge product. That means it is an improvement that consumers can get while they are waiting for the BIG improvement due out later. In this case the next big thing is code-named Prescott. If Prescott comes out in the fourth quarter as expected, then the Extreme chip will fall in price at that time. That would be my typical time to buy. But it is unlikely Intel will have product in the supply chain in time for Christmas.
So I guess I hang tight and hope "The Kids' Machine" can keep chugging along a little longer. Then of course there is the "spousal approval" game that must be played out...but that is a whole new ball game.