Wall Street's optimism in last week's preview about the earnings of tech stocks wasn't misplaced, as there were many more positive surprises than negative ones among the stocks we looked at. This week will bring plenty more data for investors in and watchers of the sector to mull over. Apple Inc. (NASDAQ: AAPL), AT&T Inc. (NYSE: T), and Microsoft Corp. (NASDAQ: MSFT), for example, are expected by analysts surveyed by Thomson Financial to post modest earnings gains from a year ago, to $1.11 per share (on $8.1 billion in sales), $0.72 per share (on $31.3 billion in sales), and $0.47 per share (on $14.8 billion in sales) respectively. All three of these companies ended the week closer to their 52-week lows than highs, and analysts on average consider them each a buy.

Here's a look at some of the week's biggest expected earnings gainers and decliners in the sector:

• Baidu.com Inc. (NASDAQ: BIDU): $1.25 per share (+44.0%) on revenues of $134.7 million (+103.2%)
• Broadcom Corp. (NASDAQ: BRCM): $0.44 per share (+38.6%) on revenues of $1.3 billion (+33.8%)
• QLogic Corp. (NASDAQ: QLGC): $0.31 per share (+29.0%) on revenues of $170.0 million (+21.2%)
• FLIR Systems Inc. (NASDAQ: FLIR): $0.32 per share (+28.1%) on revenues of $275.2 million (+44.0%)
• Juniper Networks Inc. (NASDAQ: JNPR): $0.30 per share (+26.7%) on revenues of $927.4 million (+26.2%)
• Waters Corp. (NYSE: WAT): $0.75 per share (+17.3%) on revenues of $391.6 million (+11.1%)
• Flextronics International Ltd. (NASDAQ: FLEX): $0.29 per share (+17.2%) on revenues of $8.7 billion (+57.3%)
• EMC Corp. (NYSE: EMC): $0.19 per share (+10.5%) on revenues of $3.7 billion (+12.9%)

MOST NOTEWORTHY: Marvel Entertainment (MVL), AutoZone (AZO), Home Depot (HD), Molson Coors (TAP) and Semtech (SMTC) were some of today's noteworthy upgrades:

• Matrix upgraded Marvel Entertainment (NYSE: MVL) to Buy from Hold as they don't think the company's improving performance is reflected in its falling stock price. They think Marvel represents a good entry point at current levels.

• Kevin Dann upgraded shares of AutoZone (NYSE: AZO) to Buy from Hold on valuation and highlighted their belief that AutoZone may not be seeing as much sales weakness as investors expect. They recommend taking advantage of the recent share weakness and raised their target to $135 from $125.

• Gabelli recommends Home Depot (NYSE: HD) as a long-term buy with a $43 target, upgraded shares from Hold, with the Supply division uncertainty now eliminated. They view the sale positively, even at the lower price.

• JP Morgan upgraded Molson Coors (NYSE: TAP) to Overweight from Neutral, and believes Molson will monetize its solid balance sheet and free-cash flow yield to benefit the shareholders. They also consider valuation to be attractive.

• Semtech (NASDAQ: SMTC) was upgraded to Outperform from Market Perform at William Blair following the strong Q2 report and outlook...

OTHER UPGRADES:

• Big Lots (NYSE: BIG) was upgraded to Market Outperform from Market Perform at Avondale.

• Longbow raised TTM Technologies (NASDAQ: TTMI) to Buy from Neutral.

• Breen Murray raised to Intevac (NASDAQ: IVAC) to Hold from Sell.

• Stifel upgraded Arch Capital (NASDAQ: ACGL) to Buy from Hold.

Analyst summaries provided by TheFlyOnTheWall.com (subscription required).