Multicore technology represents more than just a performance upgrade over single core chips. It's a transformative technology set to alter the underlying structure of enterprise systems, which means you better bone up on how to handle them before they take over.
And take over they will, with most new desktops already sporting dual cores and a new generation of quads ready to hit the market in 2008. Under typical purchasing cycles, you should see the number of multicores double in your organization every three years.
A good place to start is this short but insightful article by Jack Gold on eWEEK. He points out that applications will need to be reworked to take advantage of multicore's benefits, so it would be wise to check with your vendors to make sure they are ahead of the curve.
Despite recent troubles with the AMD Barcelona chips, the march of the multicores is inevitable. It's only smart to start planning for that transition now.