If it is any consolation the boys wanting to play with their big blocks XT toy will be able to run it as a Sidechain, in a sandbox, keeping the mess to a minimum. And we can all learn valuable things for when bigger blocks make sense.
Dead right. I'll happily use XT as a sidechain, and especially if others are going to subsidize my activity in exchange for my allowing them to spy on me. None of my BTC input is going to be red-listed because I can account for all of it, and I'm happy to register my XTsidecoins for buying all kinds of trinkets under the watchful eye of Big Bro. As long as any frozen XTSC I hold eventually auto-revert to BTC in the case of a taint freeze-out or other failure I'm as happy as a clam.
I've a strong suspicion that interest in sponsoring XT will dry up if it cannot be the primary source of truth in the crypto-currency space, and it looks a lot like sidechains will beat them to the punch allowing Bitcoin to remain (and significantly extend) it's distributed infrastructure support base.
Way to go Blockstream. You guys rock! Not even all that far off the schedule I predicted near the beginning of the year IIRC.