I think the reason why they say the "ex" date for shares is because they are saying all outstanding shares at the end of that date.
In this example, it is for all outstanding shares on Jan 10th. Whomever holds these shares at the close of trading today will recieve 1 share for every 2 they hold.
In other words, any option exercises, warrants, secondary offerings (which there are none) done after this date would not be eligible for the split (if they were done). Basically any shares offered after Jan 10 in this case are not eligible for the split. I am not aware of any and likely there is none but I believe that is the reason for this. I am not sure if warrants are price split adjusted or if 50% more are available.
If I am wrong or did not explain this well, please feel free to comment.
Disclosure, currently long 700 shares. well...1050 tomorrow. :)