Anyone you are impressed with that we should be looking out for?
I don't follow that much, so I can hardly say that I know well the junior scene. But I do watch a match or two at the very least in the majors. Mostly when there is a Brazilian on court.
Back to your question, rigth now, no one even close with to the vibe I got when I watched Fonseca for the first time. RG junior champion Luis Miguel will probably be very good for our standards, and I do believe he has way more potential than Lee or Hewitt. He did get better results than both in either junior or professional tournaments, and he is younger if I am not mistaken. But I would not affirm he is a shoo in for a future top 10 spot. Potential he has, but it could go in a lot of different ways.
Fun fact, LM will play Nick Kyrgios today in an UTS exho, on clay. I expect him to completly demolish the Australian, no matter how good he might serve.
Miguel was double champions in Wimbledon together with a kid named Ziga Sesko, from Eslovenia. I was impressed with him, but one doubles match, in which they were vastly superior (seemed different categories), is too small a sample... I will try to catch another match if I can. US Open is not far.