It's a DEVELOPER conference, so it's focus has always been about guiding and helping developers. This means, in most cases, that it's all about software and software platforms. The only time hardware is mentioned is to announce a totally new platform (iPhone1), or Macs (I suppose because they are a development tool, or a pro tool).
My point is, not gonna happen. There will be no new iPad generation announcement at WWDC. If there is, I will eat my right shoe. (already ate my earlier due to a misprediction on this forum) 😀