The designer's Station Plaza scheme - which includes education facilities - has had to be revised after the government announced changes in its education policy.
Hopkins' development, which was approved last August, was set to include more than 100 town-house apartments; retail and restaurant space; and a school.
But a decision by Minister for Schools Jacqui Smith has changed the town's education requirements.
A statement from the Sussex Learning and Skills Council said Smith's announcement had 'opened the door to a massive opportunity for individuals, employers and the wider community.'
The project's organisers have claimed its original 2009 date of completion will remain the same.