Already several deformable mirrors are in use at Paranal and more will come in the next years. With the next generation and telescope and associated instruments, adaptive optics become an integrated part of the telescope and provide as such the first layer of image correction. The M4 E-ELT has been specified to provide a good image quality under average seeing but it is also clear that going to larger field of view or when looking for higher performance additional deformable mirrors need to be implemented in the instruments. We present here how the needs in term of performance have evolved in the last decade. After a description of the performance for the future ELT M4, a review of the parameter space will be outlined and the development plan presented.