Promoman actually makes a very good point, underscoring something I wanted to say earlier but didn't...it's entirely possible that, aside from being primetime specials (and having better cash bonuses for everything), the upcoming nighttime shows will be just like the 1986 specials. Think about it:
In Bob Barker's era, they started with nighttime specials in 1986 that (to my knowledge) had no differences from their daytime counterparts except that they introduced the new formats for several games such as Danger Price, Any Number, and Lucky $even. After that, TPiR disappeared from primetime for 16 years, until the Armed Forces specials in 2002. Once again, they were identical to their daytime counterparts in every way, except of course that audiences for those shows were all from one particular branch of the armed forces, and that the cash bonuses received influxes. Those were followed a year later by the first round of Million Dollar $pectaculars, which (usually) were open to all audiences, and offered the $1 million top prize on the wheel. As has been previously stated, however, this makes the Showcases VERY anti-climactic if no one gets the dollar in either Showcase Showdown.
In any event, it seems logical to conclude that they might take the same road in the Drew Carey era, and that the upcoming primetime specials are the very counterparts to the nighttime specials from 1986. Plain and simple, ordinary nighttime shows, without a special gimmick (other than the obligatory bigger cash bonuses). This, as Promoman suggested, will show Drew how he is in normal daytime, which will hopefully have the effect of drawing in more viewers. Then again CBS might decide to use the Million Dollar prospect to draw in viewers who haven't seen Drew, and when they tune in and see how he does, they'll follow it to daytime. If CBS' intention is to get people to tune in during the day, then they may want people to see how TPiR looks and feels now, and they may indeed do as Promoman suggests and leave the studio alone. If their intention is to steal viewers away from other networks, they may resort to some of the same things they did on the last few primetime specials and basically create a custom MDS set.
I could go on forever ad nauseum about the possibilities, but I'm too tired to do so right now...tomorrow on the other hand...