Abbott Laboratories ( ABT) downgraded at Wachovia to Market Perform. Estimates also cut, as the company is facing several challenges at its key franchises. Broadcom ( BRCM) initiated at UBS with Buy rating. Price target starts at $47 and FY 2008 EPS estimates set at $0.47. BRE Properties ( BRE) upgraded at Credit Suisse to Outperform from Neutral. Cites high portfolio quality at discounted valuation. Raised target price to $65 from $50. Celestica ( CLS) upgraded at JP Morgan from Underweight to Neutral, JP Morgan said. Valuation call, as the stock is trading near tangible book value. Downside appears limited from current levels. FirstFed Financial ( FED) downgraded at Friedman, Billings, Ramsey from Outperform to Market Perform. $50 price target. Credit costs will likely continue to rise. Share buybacks have yet to support the stock. Marvell Technology ( MRVL) initiated with Neutral rating at UBS. Price target starts at $18 and FY 2009 EPS estimates set at $0.27. Nuance Comm. ( NUAN) downgraded at Citigroup from Buy to Hold. Valuation call, as the stock is up 92% year-to-date. Fundamentals remain healthy. Sandisk ( SNDK) downgraded at Oppenheimer to Neutral. Advantages that the company has enjoyed will likely begin to unwind, heading into 2008. TTM Technologies ( TTMI) downgraded at JP Morgan from Overweight to Neutral. Decline in the core business will not improve enough to move the stock higher in the near term. Estimates also cut.