Typically, Google doesn't enable AdWords advertisers to place certain HTML entities in their AdWords ads. In the past, placing stars or other HTML entities that make an ad or listing stand out was not allowed. Google typically just prevented them from showing up in either the AdWords or organic listings.
Darrin Ward spotted [Regus] using HTML entities, specifically the outlined black star, which looks like ✭ and can be created by using the syntax ✭ or ✭ in the ad entry form.
Here are two pictures:
I wonder how long it will last. We know Google and other engines were quick to remove this from happening in the past.
Forum discussion at Search Engine Roundtable Forums.