WIAI changed to classic hits under Key Broadcasting back in 2001, I believe. The station ran out of Danville but was aimed at the Champaign-Urbana market. It was said that Key's co-owned 98.5 WACF in Paris, despite the fact that the station was only 10 miles outside of Terre Haute, would gear it's programming toward the Danville market to fill the country void left by WIAI. The station was "blah" to say the least, but more than likely, wasn't the fault of the people who were programming things over there. Key may have stepped things up a bit over the years, but the company's Indiana and Illinois operations in 2001 and 2002 were lackluster to say the least and made horrible business decisions.
I think a year or two after the switch-over, they sold the station to Saga and moved the studio to Champaign. Shortly after the acquisition, they relaunched as "Extra 99-1" with classic hits. Not too long ago, Extra's playlist got tightened up a bit, and they began "The rock of the 80s and more" approach. The station is really sounding good these days, and it looks like it's finally starting to catch on with Champaign/Urbana listeners.
As for the other Danville stations you asked about, WITY is adult standards (with Westwood One's Adult Standards format) and WDAN is talk.
Other than that not much has changed in Danville besides the addition of two LP FMs. 105.7 runs and urban AC format and 107.5, I believe it's licensed to Bismarck, calls itself "Musicradio 107.5" and consists of 50-80s oldies during the week and 50s-70s oldies on the weekend.