George Shultz tossed his annual State of the World party last night, and visible or not, the Soviets were the biggest presence of the evening.

Soviet Ambassador Anatoliy Dobrynin, whose imminent departure from Washington after 24 years was announced this week, didn't make it back from Moscow in time for Shultz's salute to the 153 chiefs of foreign missions. But his ears should have been burning.

Talking about U.S.-Soviet relations, Shultz said, "We do have a dialogue going with Moscow . . . the dean of the diplomatic corps is not here tonight, and we welcome him in his new role. He has been part of this ongoing process, and no doubt, I hope, we will be seeing him in his new occupation."

Dobrynin's promotion this week to a senior position on the Communist Party Central Committee fueled speculation among Washington's diplomatic corps not only about what it all means but also about who will succeed him. The name that came up most: Yuli Vorontsov, currently the Kremlin's man in Paris.

The Soviets' presence at the planned summit in the United States also had officials talking. But Ambassador Max Kampelman, head of the American delegation to the arms control talks in Geneva, was sure Soviet leader Mikhail Gorbachev would be coming.

"It's just when," Kampelman told State Department spokesman Bernard Kalb.

"If I gave you a calendar," asked Kalb, "would you throw a dart?"

"Sure I would," Kampelman said.

At that point, up walked Oleg Sokolov, the Soviet Embassy's minister-counselor here. Kalb told him that Kampelman had just given him the exact date for the 1986 summit.

"He bet me $20, and I took it. But I can't tell it to you. I'm sorry," Kalb teased.

"It's all right," Sokolov replied. "It depends on us anyway."

Besides such high-level speculation, the attention of diplomats and State Department and administration officials was captured by food. Nothing far-out or ethnic, just a typical lavish State Department buffet: Hundreds of tiny lamb chops, yards of smoked salmon, dozens of elaborate cakes.

Muttered one veteran State Department observer as he took in the gourmet scene in the State Department's elegant diplomatic rooms, "Thanks to Gramm-Rudman, we'll probably have a barbecue next year."

Shultz paid a tribute to Olof Palme, the Swedish s prime minister who was assassinated last week in Stockholm.

"He was an outstanding man of peace whose goals were the goals we all seek," Shultz said. "He was struck down -- why, we don't know yet. There is no self-serving justification of any kind that can excuse such a heinous crime."

Shultz went on to say, "Terrorism has become a mode of warfare for some states who think they can mask their involvement, but they cannot. We must identify them, isolate them."

Responding to Shultz's remarks was Swedish Ambassador Wilhelm Wachtmeister, acting dean of Washington's diplomatic corps in the absence of Dobrynin and by reason of seniority his expected successor.

"It's an irony of history that just such a man as Olof Palme should be a victim of violence," Wachtmeister said.

The Swedish envoy also said that "improved contacts between the United States and the Soviet Union" are particularly encouraging to the rest of the diplomatic community.

As to the speculation on Dobrynin's successor here, Sokolov insisted that "it's not determined yet." He said Dobrynin will bring the name with him when he comes back in a couple of weeks to wind up his affairs.

One source, however, said the State Department already had been informed that Vorontsov is coming. Diplomats being diplomats, those who know Vorontsov steered clear of making comparisons, although French Ambassador Emmanuel de Margerie said both Dobrynin and his former subordinate are "highly intelligent."

Israeli Ambassador Meir Rosenne said Dobrynin's appointment to his new post "proves the importance the Soviet Union places on its relations with the United States."