Well, to be honest, I think the idea is not for the newbies to make useless posts, but to actually contribute.
Idea is good, but the implementation may need some improving - most interesting discussions are outside the newbie forum (off limits to newbies) and as for "need 4 hours of reading time" - if you've read all the interesting stuff before joining while still a guest, this will turn rathet into "4 hours of occasionally reloading the pages without actually reading much of anything and doing completely different stuff in another browser window"