So I thought that I'm set to purchase a Macbook pro 2.53 Ghz 13.3 inch replacing my Rev A Macbook Air 1.6 Ghz. However, I realized through the macforums buying guide that the Macbook pro is nearing its cycle end and will probably get a microprocessor update (Arrandale) by jan/feb next year that it would probably be a good idea to wait until then. The problem is though I'm selling my MBA for $750 (not through ebay) and by the time that MBP gets a refresh the resale value of my MBA would go down significantly (I'm guessing 200-300 dollars). Also, the MBP is on sale right due to black friday discounts. My question is, is the update (Arrandale) worth the wait and the extra cash? I've tried to read a few articles about it seems as if it stresses more on lowering the power consumption vs. super jump in performance. Is this true? I know that the MBP especially the 13.3 inch one would remain dual core instead of the quad core.