Here is an interesting report that deals with the emigration from the Baltics. The trends do not look good as the article predicts that emigration could further increase as it is becoming easier to leave the country due to established communities elsewhere. This is in addition to the worsening birth statistics in the post-Soviet countries.
An interesting parallel can be drawn with the emigration from the Lithuanian part of the Russian empire more than 100 years ago. Wikipedia states that back then between 30% and 50% of emigrants returned, this report estimates that returnees are at around 40% of all current emigrants.