This is not working for me. I've deleted the techniclauncher folder, and downloaded the latest jar. After launching, I first select the Tekkit Lite option, and it starts downloading the mods. Soon after, another window pops up with "Hello" in the title, and it just sits there with both windows blank until I force quit.
This is with no other packs ever chosen. However when I switched to classic, the whole download and launch process worked normally. I still can't launch lite.
EDIT: So I've tried several times, and left it alone with the "Hello" window open for a few minutes. It looks like that eventually it starts working. It just seems to get stuck on launch. So wait about five minutes, and hopefully it finishes launching.