The below provides some historical perspective on Disney spending approximately $3B over 5 years (
$600M per year).
From 1971 to 2001, the annual average domestic Parks & Resorts investment was
$665M in inflation-adjusted dollars.
Excluding two cruise ships, the average has been about
$200M in inflation-adjusted dollars since 2002.
A jump from $200M to $600M represents an appreciable investment in WDW and DLR, close to Disney's historical average prior to 2002.
In the first half of fiscal 2017, Disney spent
$443M in growth capex. That includes the cash to finish Pandora plus all the work going on at DLR, DHS, CSR, and CBR.
Starting with the opening of Pandora earlier this year, the next 5 years represent the most exciting time for WDW fans since the opening of DAK in 1998. For those of you too young to remember, this should give you a sense of the excitement surrounding WDW in the 1970s, 1980s, and 1990s.