Both Walmart (WMT) and BJ's Wholesale Club (BJ) reported strong quarterly results last week, suggesting that discount retailers are still doing well even as the economy seems to be coming around. This week, Costco (COST) and Big Lots (BIG) take their turns in the earnings spotlight, and analysts surveyed by Thomson Reuters expect a strong showing from them as well.

And we'll round out this preview of the coming week with a look at expectations for AutoZone (AZO), Canada's big banks, and Trina Solar (TSL).

MOST NOTEWORTHY: Toronto Dominion, Cytec Industries, Ceragon Networks, Micron and Navteq were today's noteworthy downgrades:

• CIBC downgraded shares of Toronto Dominion (NYSE: TD) to Sector Performer from Outperformer following the Commerce Bancorp (NYSE: CBH) acquisition, as they see integration risks and believes the deal will limit the company's ability to buyback stock.
  
• Cytec Industries (NYSE: CYT) was downgraded to Hold from Buy at Jefferies, as they believe near-term risks to demand and margins could bring a better entry point by 1H08. Target lowered to $75 from $79.
  
• Collins Stewart downgraded shares of Ceragon Networks (NASDAQ: CRNT) to Underperform from Buy on valuation and uncertainties surrounding the stock, which include the NEC infringement issue and increased competition.
  
• Micron Technology (NYSE: MU) was downgraded to Accumulate from Buy at ThinkEquity. The firm is cautious on the sustainability of PC related demand and questions component order levels relative to PC sell through.
  
• Banc of America downgraded shares of Navteq Corporation (NYSE: NVT) to Neutral from Buy following Nokia's (NOK) proposed buyout.

OTHER DOWNGRADES:

• JP Morgan downgraded Companhia Vale do Rio Doce (NYSE: RIO) to Neutral from Overweight.
  
• Goldman removed Johnson Controls (NYSE: JCI) from its Conviction Buy List.
  
• Citigroup downgraded GameStop Corp (NYSE: GME) to Hold from Buy.
  
• Friedman Billings downgraded Brookfield Asset Management (NYSE: BAM) to Neutral from Outperform.