I've only owned my FZ20 since December, so I'm not inclined to spend extra money upgrading at this point. I would rather wait to see what happens with the camera that replaces the FZ30 and see if noise issues are improved by use of a larger sensor. If that doesn't happen either with Panasonic cameras or with others, then I think I will be looking at a digital SLR to supplement my FZ20.
If I were interested in the FZ30, I think I would be looking to take some shots and post process them with Neat Image and see if the noise is an issue. I do wish the FZ20 had the flipup/rotating LDC as I really enjoyed that feature on my Sony DSC s-30 (one heck of a good picture taking camera!). IF Panasonic can make a significant improvement in noise levels, the successor of the FZ30 could be as market shattering as the first Canon Digital Rebel.