Hello my friend.
i got that remarkable lens with the EPL1, i have used it for now about 7 weeks, 2 weeks with the digital view finder, and 5 weeks using the live view.
(1) for the auto-focus, i think it is great and really fast, comparing to the 4/3 Olympus 70-300mm lens which i use to use it with the adapter. as a matter of fact no comparison. and i have to say that i am not good in using auto focus generally and most of my shots with other lenses is done manually but this one is really fast.
guess it will make susper combination with the EPL3 which is side to have the fastest auto-focus ever.
(2) all Lumix m4/3 lenses can be used with the pen cameras, just like Olympus's m4/3, and both the 4/3 Olympus and lumix lenses has to be used with the adaptor.
(3) although the Pen bodies got in body IS, but for long reach lenses turning on the OIS is a must, and it sure make the IQ much better.
check these images form my gallery
http://www.birdforum.net/gallery/showphoto.php/photo/377710/ppuser/71763
http://www.birdforum.net/gallery/showphoto.php/photo/376912/ppuser/71763
http://www.birdforum.net/gallery/showphoto.php/photo/377567/ppuser/71763
these all are with the OIS on.
this one
http://www.flickr.com/photos/ammadoux/6001320788/in/photostream
here Accidentally the OIS was off, and as you see it is a bet soft, although i got the f at 8.0.
btw, although this lens has OIS, while the similar Olympus's m4/3 75-300mm do not have, the lumix got less price.
i hope that helps.
