Apple’s own Black Friday discounts may have been modest, but authorized resellers more than made up for the difference in what analysts are projecting as “huge” Mac sales from Black Friday 2009.

Kaufman Bros. analyst Shaw Wu has issued a note this morning reporting low inventory and Macs out of stock at many resellers, according to AppleInsider. Wu previously forecast 2.9 million Mac sales for the December quarter, and now says his estimate could be low.

“Promotions through third-party retailers including Amazon.com, Best Buy, Wal-Mart and Target were more aggressive than usual,” Wu explains, “with discounts as much as 20% versus previous years of 11%-13%. Some even bundled generous gift cards (as much as $50 for iPods and $150 for Macs) to entice buyers. So far, many third-party discounts (though maybe not as aggressive) are continuing beyond Black Friday.”

Indeed, AppleInsider has updated their Mac Pricing Guide to show that resellers are extending deals through the “Cyber Monday” event today. Wu also noted that foot traffic at Apple’s retail stores was “strong” and that sales of Macs, iPhones and iPods appeared brisk. Traditionally, the Black Friday weekend accounts for nearly 10% of all holiday sales.

On the flip side, Piper Jaffray analyst Gene Munster initially said Monday that Black Friday retail sales were slower than 2008 for Apple based on their own in-store checks on the day after Thanksgiving. They have since updated their information to note that online sales were up 39% from last year, which likely offsets any decrease in sales at the retail level.