This time, AT&T will have to play catch up: MCI, the nation's second largest long-distance company, today announced details of anInternet serviceit plans to offer in January -- the first Internet service that will benefit from a major national ad campaign. In addition to setting up e-mail accounts and a news service, internetMCI will offer online shopping using credit cards and extensive consulting services for businesses who want to hop on the Net. MCI will also provide consumers with one of the most advanced and graphical browsers of the World Wide Web: Netscape. The move follows an announcement by software giant Microsoft, which hopes to use easy Internet access as a way to sell its new online service -- The Microsoft Network --when it debuts in mid-'95. MCI's advantage: It operates a worldwide communications network that can be used for Internet hook-ups. While MCI seems to be doing just about everything right,TIME Science Editor Philip Elmer-DeWittsaid today it's pricing policy -- charging an hourly rate -- puts it a disadvantage in competition with many Internet service providers like Panix.Post your opinion on theNew Mediabulletin board.