The new Fantasyland was announced in Sept. 2009. Completion in Q2 2014. It is a 4+ year project because they are spreading the "capital expenditures" over as many years as possible to lessen the impact on any single years profits.
Universal found themselves in a situation where they had to dump potter profits before July 2013 to avoid a hefty tax bill. They didn't even really want Transformers because of it's similarities to Spider-man. But needing to dump cash quickly, and having a "plug and play" attraction like Transformers that they could have done by tax time because the R$D was already done of Singapore/Hollywood. Transformers, was a perfect fit for what they needed done. AND it gives them a HUGE draw to bridge the gap until Potter 2.0 opens. It's a win-win for Universal.