I'm sure there are different types of HN users, but I would never have reached 1k karma by submitting stories. I go to HN to read news, not make news. Now, that might be good or bad, depending on your perspective.
I guess my point is that it will be much harder to reach 1,000 karma by commenting. Since it seems like this is board wide and not story based then you really need to think which of two or more interesting stories you are going to comment on.