Yeah, I obviously can't speak for everyone, but as probably the biggest Wagner sceptic on this forum since forever (along with, ironically, you!) I don't think he should be dropped right now. His performances since his recall have been satisfactory and although I don't think he'll maintain those figures, there has been virtually no pressure put on him from those immediately below him in domestic cricket. I don't think people are looking for alternatives so they can drop him immediately regardless though; they're looking for alternatives because he's not really good enough so one is inevitable, probably sooner rather than later. As it stands there aren't any particularly good ones, but if there were I and probably you would be keen to axe the guy.
It's really just a wait and see proposition on the bowlers in domestic cricket. The ones that really could've threatened Wagner immediately have produced:
Gillespie - 16 @ 40
Milne - 6 @ 39
Bracewell - 9 @ 43
They've been so poor that we're talking about the likes of Bennett, Henry, Neesham and Wheeler as alternatives.. not because they should really be in the frame right at this minute, but because the Wagner expiry date has probably been pushed back a bit by the next in line guys not really doing anything, so the players with more to do (either through lack of experience or just coming back into cricket) have come into the equation as potential successors.
Zinzan is probably a bit different, but for everyone else I think the "who will replace Wagner" discussion is just a realistic assessment of Wagner's limitations moving forward, more than a impetuous need for Wagner to never play again.