I'd say the both have the same idea - to create an intermediate (and single) point of access to the value services. At this point additional operations maybe carried out. GoF Proxy doesn't specify who is Subject and who is Proxy but BusinessDelegate operates mostly between Business tier (SessionBeans) and fron-end (Web and others). BusinessDelegate maybe implemented either by Proxy or by Adapter strategies. (btw, there's no big difference between Proxy and Adapter sometimes)
SCJA, SCJD, MCSD
subject: What is the design pattern of transition delegates?