Not all DSLR's overheated, just the Canon 7D, and that was fixed with a firmware update (I own one). Over heating in a video camera format has never been an issue, the least of my worries.
I do think the $5k price tag is pushing it. Not totally unreasonable, as you're getting a ton of nice video camera form controls and such. But if you don't need built-in NDFs, XLR connectors, etc, you can go with the GH2 for much cheaper, if the DSLR form works for you.
I love the look of my 7D, but I do miss the 4:2:0 sampling of my HPX-170 (which is up for sale). Makes shooting green screens more sensitive. But the DOF I get out of my 7D, interchangeable lenses (which I don't do much of, I survive just fine with two lenses), and cheaper-then-P2 storage is nice. I'm not thrilled with recording my original footage in H.264 format, way too much compression for my personal tastes. But a nice image, nice control, but really touchy.
CMOS makes us work to avoid rolling shutter, but to some it's worth the trade off. CMOS scan rates are getting faster, and it's becoming less of an issue. I'm very anxious to see what rolling shutter and such issues are like on the AF-100.
I plan on getting this camera if it proves to get good enough reviews. Lots of info on DVXuser.com, also.
Only time will tell how this camera performs in the real world.
$5k is typical for this level of cam, but I do think Panasonic is pushing that price a tad bit. But then I look at the scopes built in, and I think it's well worth it. Those scopes built into the camera are GOLD!