Dennis Miller, really?
The guy was funny on HBO but as a 3 hour radio show it's just a total borefest. I can't see him toppling Rush. Say what you want about Rush, but the guy is a radio pro and knows the mechanics of being on the air. This is something that gets repeatedly lost on the higher ups at all the networks, is that you can't take a guy with no experience and throw him on the air just because he is entertaining somewhere else. A 3 hour daily radio show, especially talk, is a lot to do. Way different than a recorded hour a week on TV.
There is a reason that Howard, Rush, Imus and Opie and Anthony among others did well besides the fact they could entertain. They knew the mechanics of doing radio and holding an audience. Nobody did the tease and break better than Howard, stringing along those quarter hours, keeping them tuned in.
These "insta-syndicated to 200 markets" hosts just don't have that finesse.