When deciding between an e-ink display and an LCD one, you'll currently need to take into account the difficulty of looking at the latter in bright sunlight. Anti-reflective coatings exist, but are usually films applied after the fact. VISARC (Variable Index Single-layer Anti-Reflective Coating), however, is a treatment process that coats screens in a thin layer of particles that drastically cut glare. Oxford Advanced Surfaces, which makes VISARC, says that its coating can reduce reflectivity to 0.3 percent, significantly below the industry target of 0.5 percent or the average current device reflectivity of 1 percent.
Much like the waterproof coatings currently showing up in demos, VISARC is designed to be licensed to major manufacturers rather than applied by the company or customer. The coating is currently being demonstrated to potential buyers, so it's possible we'll eventually see it join waterproofing as a helpful add-on to electronic devices.