I can expect exactly that. Sidechains are just altcoins without the get rich quick scheme.
Please do tell which specific altcoins features cannot be implemented as sidechains.
That isn't the question. The question is "what altcoin would you *want* to implement as a sidechain". Sidechains are a solution looking for a problem - one which doesn't exist IMHO.
Take a look at this article:
http://insidebitcoins.com/news/sidechains-could-turn-bitcoin-into-the-reserve-currency-of-the-internet/27132The title of the article is "Sidechains Could Turn Bitcoin into the Reserve Currency of The Internet".
There are 2 problems with this title in my opinion.
1: A reserve currency is an monetary concept, not a technology one
2: Monetarily, Bitcoin ALREADY IS the reserve currency of the internet because all other currencies are priced in it on exchanges
Also, I wouldn't agree with the idea that "the real world tends towards one currency". In fact the real world tends towards diversity in all aspects. Just because you have "common" currencies doesn't mean they can't be diverse.
Re. this....
In other words, you have to deactivate bitcoins if you want to issue a new currency on a sidechain. This means that the new cryptocurrency is effectively backed by bitcoin. For example, you could freeze ten bitcoins and create 40 litecoins on a sidechain. Those litecoins then trade at 0.25 BTC rather than having their own exchange rate
...what's to stop the market independently valuing the sidechained alts where there are liquidity deficiencies in one sector and excesses in another ? I realise that Bitcoin's value just gets adjusted in response and everything evens itself out, but that's what happens at the moment anyway. I don't need to "lock up" any bitcoin to know that my alt currency is backed - I can see the exchange value in the markets.
Having sidechains dangling off Bitcoin just makes for a messy, ambiguous currency that's lost all its fungibility because some parts of the money supply are in demand and others aren't.
If you look at an alt currency like say Bitshares, you'll see that it already implements a concept like sidechains except much more elegantly in that it makes a proper distinction between economic value and technological value. Collateral in one currency is locked up against liquidity in another (just like sidechains proposes to do), there is no limit to the number of collateralised currencies (or "digital assets" as they're known) you can collateralise and they are potentially pegged (economically, not technologically) to a fiat value or other real world asset. The difference with bitcoin is that the Bitshares blockchain is *designed to support this economic model*. It supports all the mechanics required to properly collateralise and maintain the liquidity in the secondary asset currency. Not only that it can support a peg against an external asset (as opposed to sidechains which peg against bitcoin - the base asset) and allow it to inflate in exchange for a revaluation of the underlying currency.
All the sidechains concept is doing economically is backing an altcoin with bitcoin and guaranteeing the existence of the underlying collateral - something that can be done by 3rd party enterprises and markets (such as the Winky ETF).
