After months of mostly speculation and rumor, the Church has officially announced that the Idaho Falls Temple will be renovated. It will close in March 2015 and reopen around October 2016. The newsroom article makes it sound as though it will be rededicated at that time. The other temple being renovated is the Frieberg Germany temple.
(Source: Mormon Newsroom)
What does this mean for the Idaho Falls Temple? I feel pretty assured that the historic character of the temple will be mostly preserved. Scott Haskins has previously reported that he has evaluated the murals in preparation for this renovation, so that the Church knows what work needs to be performed.
Another aspect will be the seismic upgrade that the building will receive, which probably explains the long period the temple will be closed. I imagine the temple will also have its heating, cooling, ventilation, and other systems looked over, as well.
The trend right now is for the Church to preserve historic architecture, so I don't anticipate any of the historical elements being taken out, nor the progression in the temple being removed. It may be nice to arrange for the windows to be opened during the portions of the session that don't have film, though (as I mentioned in my earlier post).
In any case, it's good to see the official announcement, and to know that the temple will continue to be preserved.