For the most part Max, that is probably a safe assumption, but you can bet there will be new hardware that hits the market without XP drivers.
Currently, all motherboard chipsets are supported under Windows XP. Video cards, network adapters, and sound cards also still have XP drivers.
Windows XP still occupies about 70% of the Windows marketplace. Anyone not supporting it is foolish right now.
It would not surprise me to see most all hardware still being supported under XP through 2010 or 2011. There will be exceptions, as there always is.
I figure the computer I just built, with Windows XP will see me through W7's growing pains easily enough and by the next build, W7 should be in good enough shape to be useful. As it is built from Vista, it has an edge due to the number of bug fixes that have already been doen to Vista. Now with the default bloat being disabled by default and the more than stupid ways to navigate around being dropped for something more sensible, for the most part, it has a decent shot at being a decent replacement OS.
I am watching with a bit of pessimistic caution. I think Microsoft has earned that.