01/11/2008 AT 02:15 PM EST
Josh Duhamel has his life in order – he has a hit TV show, stunning good looks and new fiancée. The only complication? Planning a perfectly fergalicious wedding.
, his girlfriend-of-three-years, the TV star told PEOPLE, "We're in the preliminary stages" of wedding preparations. (As for a potential date, the actor would only say "soon.")
His fiancée, a.k.a. The Dutchess, did not join Duhamel at Thursday's 100th episode celebration for Las Vegas
at the Palms Casino Resort – but their pending nuptials were clearly at the forefront of his mind. And Vegas, being the wedding capital of the world, wasn't giving him any ideas, either.
"Right now, we're just figuring it all out," he said, adding that they haven't settled on a size or location for the ceremony. "We're just enjoying it. It's all great, though."
News of the couple's engagement first broke on Christmas Day. "I feel like the luckiest girl in the world," Fergie, 32, told PEOPLE soon afterward
. "I'm thrilled."
Also thrilled: Duhamel, whose NBC show is still going strong in it's fifth season. Joined castmates Molly Sims, Camille Guaty and James Lesure, the actor accepted the key to the city before dining at N9NE Steakhouse and retreating to a private cast party.
"We all feel very fortunate, lucky and excited to be here," he said.