Much of the spending is going to be devoted to infrastructure and operations. Things like making pathways wider, providing more cover from storms, and enhancing guest areas are on the docket. New backstage areas too.
Keep in mind that the average age of guest is getting older and older at TDR. 40 and 50 year olds have more disposable income then 20 year olds, and they may be less willing to wait in 2 hour lines. Many of the upgrades are focused on making sure they don't lose out on the aging population. Think of what MK has been doing with things like the New Hub and we may have hints into the future of TDR.
Now are they needed? I think so. Is WDW guilty of much the same stagnation as TDR? Yep. I just find it amusing people find it in themselves to praise TDR when they've been just as stagnate as WDW. DLR and HKDL have been the most aggressive in their expansions over the last few years. That's unlikely to change with DLR (Two new lands rumored, a plethora of cutting edge nighttime spectaculars, and ride and land upgrades) and HKDL (Iron Man, TSMM, Disney Explorers, and Phase Two) still advancing new offerings.