Just because they wont be supporting it isn't the end of the world, imo. It can still give you many years. If you don't use it for email or the web, it won't matter very much. (you won't be going places where it could get in trouble)
if really concerned about it, you can unplug it from the internet entirely. But leaving it connected should be fine. Your router has a firewall in it, that keeps the outside world OUT. Going out to get emails, or visiting websites, are the main ways you could get in trouble with a pesky bug.
If you keep it, I suggest making a backup of your wizard program folder. This way all of your calibrations will be saved, if you have to re-install on a new computer (with the same controller pack). It otherwise takes a lot of time to re-calibrate all the different cuts - after a complete reinstall.
We switched our 8000 over from XP to Windows 7, about 4 months ago. This required replacing the driver pack.
They are also releasing new software this week.
Some advice: Many of the Wizard 8000's that shipped with XP only had 256mb memory installed. The (last five years of) software updates call for a minimum of four times that (1gb). Memory can be upgraded inexpensively, by popping in some new chips. This will give you a huge performance boost with the software. It will make it seem like a somewhat new computer.