Ours turned yellow. We bought the house at 3years of age and the natural maple cabs were already very yellowed. Some will say that certain urethanes or whathaveyou won't turn color, but I haven't seen it.

Among woods, maple has one of the lowest tendencies toward darkening esp. if the finish is chosen toward that end.
Casey

Thank you so much for your responses! I've read somewhere here on Gardenweb that the type of finish can determine if maple will yellow or not, but I'm not sure how to find out exactly what finish different companies use. Or which finish to ask for. The man at Lowe's pointed out to me that the Kraftmaid natural maple cabinets in his store were less yellow than the ones made by Diamond. Both had been there for years. And again, he told me stained maple cabinets would not yellow at all.

Polyurethanes and nitrocellulose will yellow with UV exposure. Stick with catalyzed lacquer or CAB-acrylic lacquer. Some catalyzed lacquers can yellow, but are much more durable than both urethanes and CAB-acrylic.

Regardless of finish, maple will warm up, yellow if you like.
Finishes can also yellow but none will prevent the wood from aging. As noted it does not darken as much as other woods. Even a light stain can minimize the yellow, but whatever color the stain is, it will also get warmer with time and as light exposure affects the tannins in the wood.

I have 12 yr. old maple Kraftmaid cabinets w/ their factory Natural stain finish. I just opened up adjoining doors to compare the shade of the exposed side to that of the inside of the doors.

Side by side, the outside of the doors are a twee bit deeper in hue. But the difference is so slight that it probably wouldn't show up in a photo.

Thank you everyone for your great responses!