I know on the Disney Dish Len Testa talked about this and did look at the inflation impact and estimate that 17bn over the next 10 years is worth about 14 billion in today's dollars, so about 1.4bn a year - and based on what they have reported spending int he past is similar to what they spent over the past 10 years ... so it isn't like some huge windfall and will definitely be a 5th gate or anything, but also isn't nothing
In the past 10 years we got (off the top of my head):
- the finish of new fantasy land
- Pandora
- Galaxy's Edge
- MMRR, Guardains, Remy, Tron, Frozen Ever After,
- Some new / replacement hotels and DVC (Gran Destino, Riviera, etc)
- The Skyliner
- Disney Springs
So I think we can see that as the scale of the next 10 years