By the looks of it, and going with their usual calender dates of events...it could be early in the new year. January/February time when the Arrandale's are released. Then again they might not, the C2D they have in the machines at the moment have easily enough power to run them at least another year or two. May be a bit to early for them to jump on that particular bad wagon just yet.
...TBH iv given up trying to predict such things. Apple seem to do what they want, regardless of the market or whats hot at them moment.