The U.S. Puzzle Championship will be held on Saturday August 27, 2011 at 1pm ET. Everyone who has pre-registered (including all 2010 USPC registrants) will receive email confirmation on August 14. Registration is currently open to puzzle solvers world-wide to participate in this online event.
It's easy to forget how recently the now "standard" internet test of 48-hour open weekend arose here on LMI. While the USPC has been running for over a decade now, being a once a year thing means it may take some time to adjust to accommodate overseas solvers. It will certainly always be "live" for US competitors, but I'll forward your concern to the organizers and see if it is something they'd think of considering in the future.