Martin Sorrell, the brightest bulb in advertising, received an early Christmas gift as Dell decides to consolidate its $4.5B in billings over the next three years to a new shop created by WPP Group. His gain pretty much signifies that the era of the holding company set-up is officially kaput.

That corporate structure is based on the premise that “best teams” from a holding company’s advertising, marketing, promotion, and PR units will seamlessly blend to serve the needs of a client. That’s a pie-in-the-sky attitude.

Perfect integration rarely happens in the “real world.” Rivalries arise. Turfs are defended. The various parts of a holding company are more interested in beefing up their own profits rather than in sharing the wealth with sister units.

In that scenario, WPP ad agency Young & Rubicam might think twice before shipping marketing dollars to sister agency Hill & Knowlton. When it comes to ad savvy, WPP’s GCI Group, which does a lot of PR for Dell, may favor former parent Grey Advertising over JWT.

Dell says the new agency will assume the work of its more than 800 marketing partners. The agency that blossoms from "Project DaVinci" (code name for the new shop) will be responsible for its own P&L. It won’t be a holding company that glues teams and people together from units with their own profit considerations.

Sorrell expects to staff the new firm with about 1,000 people. They will come from within and outside WPP. He told the Wall Street Journal that DaVinci will be available to other clients. That counters the whole idea of Dell wanting a partnership with one firm. Sorrell is too smart to screw that up.

According to Dell’s announcement: “We want our partner to spend 100 percent of their time thinking about our customers, rather than how they will get the next assignment.” That is a shot across Sir Martin’s bow. If Dell demands an exclusive relationship, one can bet that Sorrell will focus laser-like on the personal computer marketer.

Bank of America may soon nail another coffin in the holding company structure. Its contract with Omnicom expires March 31. BoA has put some of OMC’s media-buying responsibilities up for review because it no longer wants to be held hostage to Omnicom's shops.

The holding company structure is bound to unravel in `08. That will create big opportunities for nimble PR firms.