I REALLY APPRECIATE the time taken to respond to my post. It's really helpful.
Here is my current crossroad to which I appreciate ANY HELP.
I shoot a lot of kids sports - mostly outdoor (soccer, football, etc) with monopod...and invest a lot of time in Photoshop and video editing afterwards....but all on a hobby budget. I bought the Olympus E-510 several years ago when it was a good entry value. Then I bought a used ZUIKO DIGITAL ED 50-200mm F2.8-3.5 (No SWD) for about $580 as so many recommended it as a great sports lens. It has been just that. Naturally it has been a matter of having invested in better glass than camera.
So now I am at a point in which I would like to get past the limits of the E-510 not in high end quality as much as simply features that so many even lower end models have - especially shooting video, but also better ISO usability for some indoor sports, sensor size, etc. (Size of camera is NOT significant....so micro-four-thirds is not a benefit in terms of smaller size.) The dilemma seems to be that few if any cameras will operate my lens effectively...in particular they would lose AF speed which would be a big step backwards in all sports shooting. From all I read, any use of 4/3 lens to m4/3 camera via adapter loses significant AF speed.) And selling my lens and re-buying another would be too costly as no lens would appear to come close to that quality without an enormously higher price. I see some high zoom micro-four thirds lenses but I assume that the jump to micro-four-thirds, plus loss of f2.8 light, plus general quality would mean some significant loss in quality. So while I prefer to change cameras in order to maintain use of such a quality lens... from all I can gather...I would lose AF speed or even functionality with any other camera. If that is the case...I would have to look at an entire shift of camera and lens. Since I could likely only get about $550 for my current camera and lenses... I would want to have new set up only total about $1000. ($400 to $500 additional).
So main crossroads: Goal of any choice is kids sports enthusiast desiring value level equipment with video potential (as many now have).Do I get more invested in a four-thirds lens (when four thirds and that lens is in particular seems to have little future)...or do I jump to micro-four-thirds when size of gear is not a factor for me and there seems to still be some limits in equal zoom / sports lens quality...or do I jump out into standard Canon / Nikon world?
Is there any more updated camera (ie. with video) that my ZUIKO DIGITAL ED 50-200mm F2.8-3.5 (No SWD) could work well with that is WORTH the cost? And would it be a good choice or is getting further invested into the four-thirds line not wise at this time when so much is shifting?
I really like Panasonic for "enthusiaists" like myself, but the compatibility chart for the high feature and well value priced Panasonic DMC-GH3 (would be my first choice in cost, video quality, bigger size. sensor size) shows "quick AF operation" in photo shooting and "AF auto continuous operation" in movie shooting are not available with my lens. Compatibility notes also states: " Though AFS Mode is available, it may be lacking in sharpness in the image or taking longer than usual focusing time. In such cases, please use MF Mode or AF+MF function." I would also appear to lose any compatibility with my OLYMPUS EC-14 tele-converter.
So...if I had to choose a direction, do you have any insights or advice regarding any of the following:
Stick with the Oly E-510 and enjoy the great Zuiko lens until better choices emerge in future such as better micro 4/3 lenses
I could jump to micro-four thirds and consider
Panasonic DMC-G5KK ($500 body and lens kit)
Panasonic DMC-GH3 ($1300 body)
with a lens such as
Panasonic 45-200mm f/4.0-5.6 Lumix G Vario ($260)
Olympus M.Zuiko 40-150mm f/4.0-5.6 ($200)
Panasonic Lumix G X Vario PZ 45-175mm/F4.0-5.6 (upper line, has power-zoom especial for movies) ($300 black - 450)
(Also: In late January 2013, Tamron announced its first ever zoom lens for Micro Four Thirds, the 14-150mm F/3.5-5.8 Di III VC. That'll let in a bit more light than the Olympus, will have built-in image stabilization, and a stopper motor, which allows for quieter focusing. Unfortunately, Tamron hasn't said anything at all about when this lens will launch, or for how much, so we may be a while from knowing if it's any good.")
I could jump out of the 4-3 / micro 4-3 world and shift to:
Canon t4i (Best Buy $900 with 18-50 lens) (Amazon $650 with 18-50 lens) (Buy.Com - $456 body only)
18MP, continuous AF for movies, Full HD
Could combine with
Sigma 70-200mm f/2.8 II EX DG APO Macro HSM Canon-ef
Amazon - shows used only at $800