Interesting article on brand valuation on 4hoteliers.com website. First off all the author is corectly placing the brand as a independent category among the intangible assets of a company:
Brand and relationship intangibles: these include trade names, trademarks and trade symbols, domain names, design rights, trade dress, packaging, copyrights over associated colours, smells, sounds, descriptors, logotypes, advertising visuals, and written copy. In addition, associated goodwill (the general predisposition of individuals to do business with one brand rather than another brand) should be included.
Then the article si focusing on several approaces to brand valuation: