Ok so im planning on getting the nikon D90 when the D5000 comes out just to see what the final price will be, should i go for just the body? i have a sigma 50mm 1.4 hsm, nikon 18-55mm kit, nikon 50-200mm all non vr
Unless you want the kit lens specifically, and are getting a good deal for the KIT package, I say get the Body only. The D5000 is a different class of camera though, so it won't affect the D90's rate at all.
I doubt the D5000 will have any effect on the price of the D90. The 18-105 kit lens would be an improvement over the 18-55 that you have, as would the 16-85. If you do want the 18-105, then buying it as part of the kit will save you $50. Your eventual lens plans should drive your decision of whether or not to opt for the kit lens.