Mites

Figured out what to search for, and it turns out that it's a harmless (tell that to my ugly leaves!) mite -- Maple Bladder Galls.

http://www.ext.vt.edu/departments/entomology/factsheets/maplemit.html

Note the end where they say it's "one of the most common inquiries received by diagnosticians." At least it's not just me!

Also, http://www.ppdl.purdue.edu/ppdl/expert/Maple_bladder_galls.html

Called the County Extension Agent

Our maple has been doing this funky thing for a few weeks, and I finally decided to call an extension agent today to see what exactly it is. They're supposed to call back between 2-3 today. I hope they have an answer for me. (I'm kinda plant-dumb.) Those little bud-looking things on the leaves start out green, then turn pinkish-red, then turn black, and finally fall off, leaving the brown circles. It's doing it on the new growth too, so I'm not thinking it's a normal part of the tree cycle.