Which brings to mind the DCA Extreme Makeover timeline.
Announced October, 2007
First phase of construction (Little Mermaid) began mid 2008
Second phase of construction (Cars Land/Pier makeover) began mid 2009
Third phase of construction (Buena Vista Street) began mid 2010
First all new ride (Little Mermaid) opened May, 2011
Project completed with Cars Land/Buena Vista Street opening June, 2012
Total time from announcement to completion, 4 years and 8 months.
Which makes me a little nervous for this weekend, because if the big stuff isn't going to be done for almost six more years it might not be time to make a big announcement at D23 Expo yet. I think we're all hoping they say something about DHS this weekend, but they might not be ready to say anything, at least about the "good stuff" coming in 2020-21.