I would define corporate ID as the organization’s look and feel. This includes item like the logo, business cards, letterhead, forms (fax, PO, invoice, etc.) and can be carried to collateral materials (brochures, direct mail, packaging, etc.) Larger companies will have corporate ID guidelines that control the usage of logos, colors, fonts, and other graphic guidelines (tracking, leading, etc.)
Brand identity is more strategic. Brand management controls the not only the look and feel of the brand (corporate, range or product level) but also includes tangible and intangible assets, functional and emotional benefits, of the company or product and what the company/product can deliver. Brand has been defined as the promise of the company’s/product’s value to the customer.
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http://www.brandchannel.com/start.asp