My main XP machine is so well set up with all the tools I require that it would be a costly exercise just to upgrade it for the sake of Microsoft.
If anything is going to kill it it will be because it's a 32 bit machine.
When I finally decide to make the move to new hardware my plan is to convert my physical machine into virtual form - probably VMWare. This way I get to keep my current setup in operational form.
I haven't investigated an easy way of converting an existing physical machine into virtual form, but I know I can shoe-horn it into there if required.