BUT if there is a new OS out, 'hackers' will be targting that rather than the old system, so you are better off with stick with what you got for at least a year or two.
Don't fully agree with that.
True, many hackers will try to find security holes in the new OS.
But on the other hand, hackers already found many security holes in "old" operating system.
And since almost everybody is using XP now, and it'll stay like that for lets say 2 years, hackers will keep exploiting those security holes.
Just because there are more possible targets.