I think the number of people wanting London theatre breaks is going to hold up even when there's not so much spending money about for some. The recession will hit some sectors more than others, and there's clearly a mood to wait for bargains. Longer holidays abroad are starting to wane in any case, with people wanting to take short breaks more frequently and UK short breaks with a West End Show hotel and rail travel all combined will continue to look tempting.
Not all of the current shows will survive though. Musicals come and go and plays have a shorter lifespan.
I'm in two minds about
Sister Act Theatre Breaks for example, and not 100% about
Oliver after the first year.
Dirty Dancing,
Mamma Mia and
We Will Rock You and
Hairspray will remain ever popular.