Well, it took quite a while but the Tyranid codex has finally been leaked - only it is the German Codex. This makes sense though since all the rumor sites are saying that the GW Black Box that shipped to all the markets except Germany didn't include the new Codex due to a printing mistake.
The rumor confirmations are starting to trickle in though - from German based gamers as well as those who live in other countries but speak German.
From what I have heard it looks like there are a TON of neat special characters in there. I haven't heard to many specifics about abilities but I am seeing great modeling opportunities.
One of the biggest things that I have seen that was pretty much already confirmed is that Genestealers remain troops and keep their old profile. Something else that I haven't seen get a lot of press is the new Harpie - a winged monsterous creature in the Fast Attack slot. I haven't heard what this thing does but I already want one. Supposedly it is some kind of flying Trygon.
On a sadder note (to Tyranid players at least) it does appear that the Carnifex does weigh in at 160 points per model now. I am not sure what all it comes with standard and what options it can take but you can take 1-3 per brood.
This is all I have for now but the floodgates are open so it is only a matter of time before all the juicy details are floating about the internet.