Speculation of new MacBook?

I sent my MacBook in on Monday for a "fix". According to the Apple website, the repair was finished Thursday. Something was wrong with the fan, or the CPU. but it was making an abnormally loud buzz/humming noise around where the CPU is located (left upper keyboard). AppleCare didnt update the Repair status on my MacBook until just a while ago. And it said it shipped today. With an estimated delivery of Monday around noon.
What i was thinking is that perhaps there is some kind of update to the MacBook at WWDC, such as a new CPU (Perhaps 3 ghz) or something of that matter. And they are waiting for that to be announced, before i get my MB back, with a new updated part.
Or maye i could just be overthinking and hoping for the best. What basically sparked this is because it is taking so long for me to get it back, and it sat, after being finished, waiting for a shipment, for 2 days.
Tell me what you think!