Absolutely nothing – the fact that the carrier has yet to collect payment, as long as this has gone through in the first instance i.e. during the booking process and you have a confirmed ticket, doesn't really mean anything when it comes to using the ticket. Again, it has happened to me (it was an Air France booking and, when they i.e. Amex eventually applied the charge, I was wondering what it referred to as I had completely forgotten about it).

G