SSD pricing is dropping rapidly. Most slates built today use SSDs and most new laptops have SSDs available at fairly reasonable prices.
Sizes are still small when compared to conventional HDDs, but the gap is closing fast.
Also, consider that local storage is going to suffer tremendously with the onslaught of cloud storage. Forget the issues with storing everything "in the cloud", it is real, it is here and it will reduce the need for large storage space locally.
I installed an OCZ SSD with Windows 7 and Photoshop. Photoshop used to take 15 seconds to load and be ready to use. Now it takes 2 seconds.