Black Fleece is a new line complementing Brooks Brothers' Golden Fleece line of suits, jackets and accessories. Overseeing the design of Black Fleece is the somewhat controversial Thom Browne. His jackets are noticeably shorter than convention, as are the legs of the trousers. In 2006, Thom Browne won the best menswear design by the Council of Fashion Designers of America.
This StyleForum thread illustrates some of his runway designs, some of which will presumably hit the stores this fall. On a more amusing note, I asked a senior salesman at one of the larger Brooks Bros stores about the Thom Browne designs. I don't wish to get him in trouble by reproducing his rather funny response but suffice to say the Black Fleece line is a break from tradition in some respects (though the outerwear shown on the runway are very traditionally English for the most part).
It's too early to tell but I think Black Fleece is a rather smart move - fresh enough to attract new, younger buyers but familiar enough not to alienate current customers.