Change in RatingsCabot ( CBT) upgraded at JP Morgan from Neutral to Overweight. Company is cyclical, and its earnings have likely bottomed, along with the peak in raw material costs. Energy Conversion Devices ( ENER) downgraded at Piper Jaffray to Neutral from Buy based on limited upside due to ramp costs associated with two new production lines that will not come online until 2009. Price target raised to $73 from $58. Energy Conversion Devices numbers raised at Jefferies. Fiscal 2009 EPS estimates raised to $1.78 from $1.63. Price target raised to $96 from $57. Maintains Buy rating. H&E Equipment ( HEES) downgraded at Credit Suisse to Neutral from Outperform based on valuation. The stock is up 17% over the past month. Maintained $14 target price. Stock Comments/EPS ChangesDell ( DELL) numbers lowered at UBS. Fiscal 2009 EPS estimates lowered to $1.44 from $1.61. Price target lowered to $26 from $27. Maintains Neutral rating. PetSmart ( PETM) target raised at Credit Suisse to $26 from $20 based on slowing store growth and expense management, which should increase earnings in the near term. Maintained Neutral rating.