They are super-clueless. Once majority of miners switch to whatever fork becomes official one, transactions related to all other forks will never ever be confirmed. Current mining difficulty is so high that other forks would stay frozen forever. But yes, you can borrow BTC from someone before hard-forking and try to trick him into accepting BTC on wrong fork but only a fool will consider perma-unconfirmed transaction as valid one.
Back to speculations, https://bitcointalksearch.org/topic/phoenixcoin-pxc-an-epic-speculation-1342936 is looking for some serious gamblers!
I'm not a techie but it's not that simple from a geopolitical standpoint which is what money is all about. Gavin and Hearn (and their bankers) have tried for over 6 months and they have even dropped it from 20MB to 2MB and still no success.
You're right that once a majority or super majority actually upgrade then it's a done deal but that's the problem, China won't allow it and now you have serious opposition from Core (and their new massive backers) . That's a stalemate if not a Checkmate for any scaling possibilities for Bitcoin.
That is a fatal flaw cause Bitcoin will never be used as a daily currency so then, the currency which everyone starts using on a daily basis, that currency will eventually gain critical mass and global adoption which will automatically kill off every other currency, including Bitcoin.
But Bitcoin is still prepped and ready to do a massive Global wealth transfer [tens of trillions of $$$]; and that's key for numerous reasons I've discussed many times. A few thousand dollars can still make anyone into a millionaire even this late in the game.
But that window of opportunity will soon be closed when the [unworldly] global media hype starts.