I agree with nano, But I also think apple is losing many sales because the current model is not worth the money, so some ppl are going with PC workstations instead. it's also causing many rumors of apple ending the MP line, which also isnt really a positive effect.
a smart thing to do would be to lower the price on the current MP. that would hint about a new model coming up, but also have many ppl pull the trigger on the current MP.