PDL Biopharma ( PDLI) upgraded at Wachovia from Market Perform to Outperform. CEO is stepping down, and the company is for sale. Stock could command $24 to $25 a share. Walgreen ( WAG) downgraded at Merrill Lynch from Buy to Neutral. Warning was driven by higher costs, though the company continues to aggressively add new stores. XL Capital ( XL) downgraded at Wachovia to Market Perform. Company has limited upside potential, with earnings almost solely being driven by the share repurchase program.