What is more likely to happen here is that Bitcoin would have to fork to deal with the 1 MB Limit. Both coins would live side by side, compete and hopefully learn from each other. First mover is not everything. A very good example is the credit card industry. The first movers were Diner's Club and then American Express. Then came the later entrants including Visa and MasterCard. The first movers are still around but with vastly reduced market share.
The challenge for the Bitcoin is to deal with the 1 MB blocksize limit before the above happens and not become the American Express or even Diner's Club of crypto-currency.
Edit: Bitcoin might even fork in the middle of a boom, like it did the last time. After all it is way easier to get consensus when everyone is getting wealthier.
Looking back at the March 2013 temporary fork event, a long time afterwards, it occurred to me that it may have been a major driver in the $266 spike (the Cyprus situation being irrelevant). The reason is that for many non-technical people the fork "proved" that Bitcoin was truly a breakthrough in software - not a clever scam. The fact that it could have a technical glitch and people from all over the ecosystem rushed to fix it, publicly on IRC, also proved that it is an honest enterprise.
However, this is a one-off proof of legitimacy. Similar events will be very damaging. There are hundreds of alt-coins of many types waiting for Bitcoin to shoot itself in the foot. Bitcoin's value is reasonably steady now and very much buoyed from its first-mover status - and its technical stability when viewed by the public. This is not something which should be thrown away because of analysis paralysis over the 1MB.