I can tell you a little about the situation in Russia and CIS.
First, there are quite a lot of Russian-English-Russian translators/interpreters here, since English is a very popular language. Most of them are rather low-paid, but often it's well deserved, because many of them are not very professional.

Most profitable (as well as stressful) is simultaneous interpretation, but translators can earn a lot too if they are very knowledgable and choose their jobs wisely.

Best paid translation jobs are in oil business, jurisprudence, and automobile industry (it can be technical documents, contracts, etc.). Responsibility is very high there, because one wrong word can lead to severe consiquences and loss of money or even lifes. Because of that good translators earn as much as 30$ per page, though it's rare. In this line of job is important to know your area and to actually understand things you need to translate. Ideally you have to be an engineer, a lawer, etc. in addition to your language skills. Otherwise you are bound to make mistakes or get confused by professional slang.

Personally I think that translating books (fiction or non-fiction) is more fun than anything mentioned above, but it will not make you rich. It's a few dollars per page if you are lucky, if even that. )

To sum it up, choose what you like most. If you want to work in any specific area be ready to put serious efforts into learning everything you can about it, in addition to learning foreign language itself.