I have a 2000 RSS and the intakes commonly do crack but most seem to be just cosmetic. FYI
if you replace it, you can buy a Barons "supposedly PORTED" manifold, but the porting is a joke. They appear to be OEM manifolds and someone hit the sharp corners inside the intake with a dremel tool very very lightly. I personally don't buy the claim that their manifold gives you 6 to 8 more horsepower. I spent a few hours porting the Barons manifold and am very happy with it now.
Here's a link if you want to do it yourself:
You may want to clean your carb
if its never been serviced, mine did need work on the accelerator pump o-ring and the rubber boot on top and while you're at it replace the float bowl needle. Pretty easy to do if you are mechanical.