OMG, whose original members in 1989 included Data General Corp., Hewlett-Packard Co. and Sun Microsystems Inc., formed in part to compete against Microsoft in the development of standards. There are now more than 700 OMG members. Most of the arguments are not based on absolute merits. Microsoft creates and manages COM and DCOM, so there is only one basic, compatible implementation. Choosing and implementing an enterprise middleware strategy is probably the most complex task any systems department will ever face.
Remote administration is vital for large installations.
The middleware must support not only your data but also all your database management tools. Scripting control is vital. Focus more on what you plan to do in the future than what you do now. The IDL level is where differences begin to show up. DCOM doesn't manage errors at the IDL level.