Sawasdee khrap, Khun Golf,
I have lived in Thailand for 17 years. According to my observation, English language skill is advancing, especially in Bangkok. Two decades ago it was difficult to find people on the street who speak English. Now the young people all speak at least a little bit of English. Also, farangs have become a common sight everywhere in Thailand. Unlike in the 80s where farangs were sometimes eyed with curious interest, occasionally even stared at, everyone seems to have gotten used to those big-nosed, lumbering, white farangs who can't walk down Sukhumvit without knocking their heads on some low-hanging items.
When I tried to start an English conversation back in those days, I would often see panic in the Thai peoples' eyes. Some would would simply freeze, others would start to stutter, or run away to get someone else to speak English. Since this was not very helpful, I quickly learned basic conversation in Thai. Nowadays, it's quite OK to speak English. Even here in Chiang Mai, many shopkeepers, students, and office people speak (at least some) English. That's good for both of us. It makes it easier for us farangs to communicate, and it gives the Thai people a window into the world by means of English books, movies, and telecommunication.