Could any of these bitcoin trash bin addresses be cracked? If bitcoins become worth millions of dollars I could see people wanting to spend long amounts of time on that.
Not by brute-forcing. Humankind will never have the kind of computing resources for that. Of course, someone might get lucky but that is about as probable as me winning the lottery twelve times in a row and then catching a deadly virus that wipes out the human population. Not sure about the exact probability of that happening, but it's similar. You would make more money standing outside and waiting for cash money to drop on your head from a friendly pilot.
There are already addresses with millions worth of BTC. I hope no one is seriously trying to brute force them right now...