Allow me to interject a fresh, new take on all of this. I have long been withdrawn of posting my opinion about Drew Carey here on these internets, but feel as if I must chime in with some analysis here regarding his hosting and the ratings.
I don't think he's cutting it. I never have thought he's cut it. And, he's going to have to do a lot in my book to improve.
Let me do an aside here. In my opinion, a good host should know his show backwards and forwards. That means just about every nuance of it. Second, you have to have the art of contestant interaction down to a science. Finally, you must realize that you have to take the show seriously, but not too seriously otherwise the show won't be fun.
Applying my above analysis to Mr. Carey, he's good at contestant interaction. He takes the show seriously at times, but other times he's sorely lacking. But, as some fans will tell you, he doesn't explain the rules of pricing games properly sometimes, and that is a problem in and of itself.
What does this have to do with declining viewership? When Drew first came on board, everyday people at my college were giving me opinions to the effect of, "I just can't get into him." And this was when he started. First impressions mean a lot apparently. If viewers tuned out in the beginning, are they going to tune back in now? I say not, but you never know. I'm very convinced the ratings ARE a problem, no matter what data you're looking at.