There is no real confirmation about extras on these new steels but the statement regarding them online says
"...The good news for those of you who don’t need to own these new collectible covers is that the Blu-rays don’t feature any new special features which means you won’t have to repurchase the films. Here is the official Star Wars steelbook press release:(a bit of it)
Each Film Presented in Unique, Collectible Character Steelbook Packaging available November 10th
.... In addition to the collectible steelbook packaging, each single disc Blu-ray includes existing audio commentary with George Lucas and the film crew as well as audio commentary from archival interviews with the cast and crew..."