If 1:1 pegs can achieve stable transfer of BTCs between chains then this is where, to me, the innovation is.
BTC can't literally be "transferred," only locked.
What you are talking about is an altcoin that is backed by BTC and is likely to have lower volatility relative to BTC than an altcoin that doesn't have this backing. (Interestingly though, this could in theory mean higher volatility relative to fiat, though in practice that would not be the case with most current alts.)
http://konradsgraf.squarespace.com/storage/Monetary%20analsyis%20of%20sidecoins%20KG%2024Oct2014.pdf but these rules are hard coded into the sidechain so one knows what to expect before moving his BTC there
Hard coded does not mean the code can't be changed. It is the same as with any altcoin. If the developers decide to change the code, and the community accepts it (without forking) then it is changed.
I have read Konrad's paper. My understanding is that he suggests the price of the BTC locked on the chain would essentially gravitate towards BTC's and most probably at a certain market discount considering cost, risk and uncertainty.