In order to ease HZ123's extremely pessimistic view of events, perhaps I can quote from the current edition of Airports of the World.
RAL's business development manager is quoted as saying, in the context of talking about the new terminal/railway station development:
"In the meantime, the existing terminal building will be refurbished shortly, allowing it to handle up to 750,000 passengers a year as a stop-gap measure until the new terminal opens in 2009. ....... further check-in counters will be added and the terminal extended forward once the car park in front of the building has been modified."
This statements seems exactly in line with the planning application lodged earlier this week, so does not seem to threaten, or even delay, the building of the new terminal. I do think that RAL has invited all this speculation, however, by not making a statement at the time clarifying matters.
Whether or not this extension turns out to be a 'botch up' or not doesn't really matter that much if it only has to meet the needs of the next 3 or 4 years.