Yes, Fred, they still make thread with the weight on the label. Sometimes it's pretty cryptic, just a number, but sometimes you'll see 50wt. I try to avoid WalMart thread in general, because as you said, it's not always good quality. But once I find a good quality thread, I buy it in quantity. Love that Aurifil! Yes, it's expensive but I have never had a problem with it and it doesn't clog my bobbin area.
Don't have a clue about the "mm" although a single m would indicate length in meters, as mentioned earlier.