Your question threw us for a moment, then we realized it must be Charlie Trotter that you were referring to; Charlie Palmer still has his restaurants at the Four Seasons (Charlie Palmer Steak) and Mandalay Bay (Aureole).
Sadly, your favorites were both victims of the recession, or at least that's definitely the case with Charlie Trotter, who closed Restaurant Charlie and Bar Charlie at Palazzo on March 19 of this year. "We just celebrated two years out there. But we opened right at the beginning of the economic downfall," stated Rochelle Smith Trotter, director of business development (and Charlie's wife), at the time.
With David Burke the story's a little more complicated, perhaps. It was on March 18 that we received notice that the Burke Group, the holding company for Chef David Burke's restaurants, had terminated its joint venture with the E-Brands restaurant group, the majority owner of David Burke Las Vegas. The announcement stated that Burke would no longer be on location at his eponymous restaurant at the Venetian nor provide any further services. Whether this was purely the result of economics or, as we sensed, some souring of the relationship between the two parties, we don't know. The restaurant has since been rebranded as one of E-Brand's Timpana Taverns. The "Burke in the Box" outlet at McCarran airport remains open.