I was thinking "Opalina" as well (the leaf is a good match) but they would have to be older plants, as Opalina normally grows a short stem (in good light anyway) and offsets sparingly.
Several of the plants in the database listing for Opalina are probably misidentified, including the one above. Here is another mismatch, probably a Graptopetalum:
The flower pictures are also straight Grapto, as are the leaves sprouting new rosettes. I will have to sit down and sort that section out soon. The key features which distinguish Opalina from a generic Graptopetalum are its wide, fat leaves; short stem; closed (bell-like) flowers; and reluctance to branch. Here is a correctly identified Opalina for comparison.
The parents of this hybrid are a Graptopetalum and an Echeveria. The fat, rounded leaves come from the former (G. amethystinum), made longer and wider because of the latter (E. colorata), which has a thick powdery dusting.
