  Future space and ground-based survey programmes will produce an impressive
amount of photometric data. The GAIA space mission will map the complete sky
down to mag V=20 and produce time series for about 1 billion stars. Survey
instruments as the International Liquid Mirror Telescope will observe slices of
the sky down to magnitude V=23. In both experiments, the opportunity exists to
discover a huge amount of variable stars. A prediction of the expected total
number of variable stars and the number of variables in specific subgroups is
given.
