For more than a decade now it has been widely appreciated that active galactic nuclei at the centers of galaxy clusters can heat and disrupt the intracluster gas on scales of tens of kpc. A variety of subresolution models have been proposed to introduce these effects into hydrodynamic simulations of cluster formation. Meanwhile, the importance of clusters as cosmological probes has motivated a number of large cluster surveys in different wavebands. These surveys rely on observed correlations between cluster observable properties and masses in order to derive cosmological constraints. What effect does AGN feedback have on these correlations? Can we exploit observed trends to correct for systematic effects and scatter in them? How important is modeling uncertainty in answering these questions? I will address these topics using results from adaptive mesh refinement simulations..