I have waxed lyrical on the AB previosly about DM - around the time of her chat show, which illustrated very clearly that she is a one-trick pony - and why she never appears in anything else apart from BB that has lasted more than one series.
People regard her as 'talented' because she fronts BB. You could put Tinky-Winky up to introduce it, and the audience figures would remain the same because (shock horror!) it's the shoe people tune in for - not her. Most of the audience are waiting for her shouty gurning prescence to vanish, so they can get on with the business of BB itself.
As long as it runs, DM will front it, but even BB will run out of steam and vanish, and so will she. Mark my words.