The interesting thing about sidechains is that the could be backed by anything.  As a matter of fact, almost anything would be a better choice than a Bitcoin which is under management by Mike Hearn since the one thing which a backing store (be it gold, crypto, whatever) cannot tolerate are fungibility problems and they are the next phase in XT and probably the next item of focus if he get's Bitcoin moved under them.

If the idea of moving Bitcoin under XT does not become DOA, I'll have to bite the bullet and start researching alts.  I doubt that the Blockstream guys are going to just crawl away and die in the unlikely event that Hearn wins and Bitcoin becomes XT.  And I suspect that the Blockstream guys will see very clearly the impossibility of using XT as a sidechain backing solution.

There is always MP's 'real core' project which, as a hodler, I would be a default part of.  I'm bored of Bitcoin as a fairly useless toy for the elite however and really would like to see a way for it to be put to a more broad use for humanity.  Without killing it of course.