Because of the landslip/landslide affecting all Worcester Park train services National Rail have just posted a timetable of the services that will be running during the day, which can be found here. The long and short of it is that there will be half hourly services running during the peak periods but don't bother using the usual link for running times as it appears to be borked.

For those that like pictures instead of text/numbers they've got one of those too: