So much going on in the rumor mill: In the midst of plenty of talk about a Macbook Air refresh, retailers are reporting that their stocks of the entry-level Macbook is running low. Is a new model on the horizon?

According to AppleInsider:

Many of the Apple authorized resellers that can be found on AppleInsider's Mac Pricing Guide are completely sold out of the polycarbonate MacBook. Specifically, Amazon, MacConnection, On Sale and J&R are all out of stock. In addition, inventory of the entry-level portable is low at DataVision.

And MacRumors also notes that, although the shortages haven't hit Apple's online store, supply drops are usually the first sign pointing toward renewed hardware. And it makes sense; the $999 Macbook hasn't been updated since May 2010. But Apple is apparently holding off on the upgrades until Lion is released. Should we expect Sandy Bridges and Thunderbolt in its future? [AppleInsider via MacRumors]