Alternative fuels and renewable energy are gaining market share as energy sources, but oil will nevertheless remain a dominant fuel for at least the next 15-20 years, which is why Nexen Inc. (NYSE: NXY) is worth a review.

Nexen, an independent, Canada-based global energy company, explores, develops and produces crude oil, natural gas, and related products in the U.K.'s North Sea, Gulf of Mexico, Western Canada, Yemen, Colombia, offshore West Africa and Norway.

While other earnings may have disappointed last week, the news was good for oil giant ConocoPhilips (NYSE: COP). In what some took as a good sign for big oil, the Houston-based company reported that third quarter net income surged 41% year over year to $3.39 per share, and that revenue also surged 52% to $70 billion. We'll see whether the good news extends to other petroleum giants scheduled to report quarterly results this week.

Analysts surveyed by Thomson Financial are looking for BP (NYSE: BP) profits to have grown 43.2% in the most recent quarter to $2.34 per share on revenue of $109.7 billion, and Chevron Corp. (NYSE: CVX) to post earnings up 39.4% to $3.25 per share on revenue of $86.8 billion. Marathon Oil Corp. (NYSE: MRO), ExxonMobil Corp. (NYSE: XOM), and Royal Dutch Shell (NYSE: RDS.A) likewise are expected to report higher net income of $2.33 per share (sales of $23.4 billion), $2.40 per share (sales of $131.4 billion), and $2.65 per share, respectively. Even Valero Energy Corp. (NYSE: VLO) is expected to post earnings slightly higher to $1.46 per share (sales of $36.4 billion), despite the effects of Hurricane Ike. Among these companies, only BP and Valero beat earnings expectations in the previous quarter. Not surprisingly, analysts on average recommend buying all except Valero, and shares of all of these companies have recently hit 52-week lows.

MOST NOTEWORTHY: Staples, Evergreen Solar and Genzyme were today's noteworthy upgrades:

• Jefferies upgraded shares of Staples (NASDAQ: SPLS) to Buy from Hold following the company's raised bid for Corporate Express based on the increased chance the deal gets deal done and SPLS achieves meaningful EPS accretion.
  
• Jefferies also raised Evergreen Solar (NASDAQ: ESLR) to Buy from Hold on valuation, as they believe concerns regarding capital needs are now priced into the stock and that the company continues to take risk out of its growth story through execution.
  
• Bernstein upgraded Genzyme (NASDAQ: GENZ) to Outperform from Market Perform citing increased confidence in GENZ's product portfolio, geographic and therapeutic diversification, improved outlook, and valuation.

OTHER UPGRADES:

• Sun Microsystems (NASDAQ: JAVA) was raised to Outperform from Market Perform at Wachovia.
  
• BearingPoint (NYSE: BE) was upgraded at Goldman to Neutral from Sell.
  
• Lehman upgraded Nexen (NYSE: NXY) to Overweight from Equal Weight.