Tattoos are definitely (seemingly) more commonplace now than they were even just 5 or 10 years ago. And more extensive tattoo work (e.g., full- and half-sleeves) in particular seem to be around a good bit more.
My take is that if the content of the tattoo is unprofessional in nature (e.g., nudity, swear words, etc.), then it needs be covered in a professional setting. Beyond that, if the dress code is adhered to, it's a toss-up. But by having tattoos exposed, you're essentially inviting folks into that (sometimes private) aspect of your life, with its associated judgments, opinions, and assumptions (founded or not). I personally try to initially put as little "out there" about myself as possible, but that's just me, and I realize that plenty of folks approach things differently.