The past is littered with all sorts of botched system transitions. Remember when US Airways consolidated its operations on the old America West system? Things may have gone well overall, but there was still a lot of pain for a lot of people during the change. Or how about AirTran's switchover to New Skies? That wasn't pretty either.
I can keep going if you'd like, but you get the point. These things are messy, no matter how well it goes. And now, it's JetBlue's turn. JetBlue has outgrown its Navitaire system and the time has come for something more robust. See, Open Skies, JetBlue's first system, was designed as an out-of-the-box startup system for low cost carriers. It does its job well, but as airlines grow up, they need to move to something else.
WestJet made the switch to Sabre and it didn't go very well. Now JetBlue is doing the same thing. They want to expand codesharing, interlining, and all sorts of other things that they can't do very well right now. So how are they going about doing it? Very carefully.
For at least 24 hours beginning on January 29 at noon Eastern Time, JetBlue will not be able to handle any reservation issues online or over the phone. It's not just reservations either. You won't be able to look up flight status, check in for your flight, or do anything with your frequent flier account. If you really need to do something to a reservation, you'll have to go to the airport.
That's a significant hit even for just 24 hours, but it shows how important this transition is to the airline. If it wasn't, they wouldn't bother doing something like this.