MacScoop claims that Apple's complete line of Macs will be updated by the end of Q2 2007. While the claim is broad and lacking in specifics, it is not unreasonable given Apple's current product cycles, as noted in our MacRumors buyers guide.
Also mentioned is a specific claim that a black version of the iMac may be introduced in 20 and 24" varieties. Of some relevance, there have been previous rumors (from ThinkSecret) surrounding the iMac being introduced in a (Product) RED variety which have yet to come to fruition.