It’s been seven months since Yamaha redesigned the official vocaloid site adapting for vocaloid3. When that redesigned happened English was left behind, forgotten. After 4 months since the japanese website release, an user from VocaloidOtaku found that an english version of vocaloid.com was under development, calling you a dummy.
Fortunately, they filled the replacement text with actual info and the website is now, almost, in english. Motoichi Tamura announced that now official information from Yamaha will also be provided in english.