Okay, we really still don't know much. We do know he was signed for $40,000. We know he's about 6'2" and we know he's 17 years old. He's not on any youtube videos; he's not on any google searches (except for other articles wondering who he is). We know he was signed by Sal Agnostelli, the Phillies Director of International Scouting and one of the best at what he does.
We also know that Eric Longenhagen from Crashburn Alley, just went ahead and called Sal to ask who this Julsan kid is. Kudos, Eric. You can read the article here.
The Phillies, as Eric notes in his article have made significant players out of insignificant signings. Of course, that doesn't mean Julsan is the next Chooch or Galvis. Sure he could be, but so could several other low profile international signees the Phillies stock up on every year.
We won't see Julsan until next year. Likely we won't really see him until next Summer when short season ball starts. He will ben Spring Training, where he can make fast friends with German born Aaron Altherr. Until then, we'll have to dream about the day he eventually starts hitting balls a country kilometer.