"As I mentioned, we routinely file intent to use trademark applications as a regular course of business, and we can't share details at this time as to how the trademarks may or may not be used," McComb said.
It's also no secret that McDonald's has been ramping up its emphasis on breakfast, which remains a big profit driver for the Golden Arches. Overall, the company has struggled to generate sales growth. McDonald's delivered a 2.8 percent drop in U.S. comparable sales in August, citing "continuing broad-based challenges, including sluggish industry growth in a highly competitive marketplace" for the drop.
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Logistically though, it remains difficult to extend breakfast hours and have them overlap with other dayparts, said ITG restaurant analyst Steve West.
"For McDonald's, the big issue is they have such heavy traffic at lunch and dinner that there's no room for breakfast items as well," West said. "That's always been the biggest hindrance for most of these companies—just the added complexity."
"Breakfast is also the daypart that customers have the highest demand for execution, because they're on the go," noted McDonald's CEO Don Thompson at a conference in May.
So until McDonald's can crack the operational puzzle of balancing service for two meals at a speedy pace, diners who want to eat breakfast later in the day might just have to settle for the regular menu.
—By CNBC's Katie Little