I respectively disagree with Sueleen.
Nuh-uh. There should be a host. Someone who represents the evening. The evening is about Broadway, and the host should be the person who makes it about that.
If it were Oprah, I'd rather have no host, however. Depends on how she'd do it.
To me, the best hosts are the ones who make the evening enjoyable, smooth, tied together, and fast. Hugh Jackman did this in 2004. (Not at all in 2003 and not so much in 2005).
I've always wanted to run the entire Tonys or Oscars. In the case of the Tonys:
1) Get a host who is funny, liked, and can take control.
2) In addition to musical numbers from shows, add one or two numbers for the host.
3) Give the host the breakdown of the evening and tell him/her to make all jokes/gags short.
But the BIGGEST change I would make is to cut the role of the announcer. That is something the HOST should be doing. The host can make these announcements from backstage if it's simply "Please welcome blah blah blah," just like the announcer does. It's ridiculous not to have the host do this. An announcer should only be used at times when the host is unavailable.
"The Spectacle has, indeed, an emotional attraction of its own, but, of all the parts, it is the least artistic, and connected least with the art of poetry. For the power of Tragedy, we may be sure, is felt even apart from representation and actors. Besides, the production of spectacular effects depends more on the art of the stage machinist than on that of the poet."
--Aristotle