Most large projects take a long time. Murano started excavation in March 2006 and they are still at least another couple months from ground level and at the very least another year and half to complete the project after that - so that's between 2.5 and 3 years of construction.
Looking backwards there was a year and a half of sales prior to that, then two years of pushing through the approvals process and likely a year or two before that with the internal planning by the developer, land aquisition etc - these large projects take a long long time to complete.