I just installed WordPress Mobile Edition 3.0, and while I think it's great overall, I've run into one critical problem: pingbacks cause a page to stop parsing.
It looks like a few dependencies on Carrington functions weren't quite removed -- or else the functions were removed incorrectly. comments/pings-loop.php is trying to call cfct_comment_list_class() and comment/ping.php is trying to call cfct_comment_class(), neither of which are defined anywhere in WP Mobile Edition.
It's worth noting that I ran into this on two blogs, neither of which uses a Carrington-based theme.
If I pull those calls out, the page at least finishes parsing, but the pingbacks themselves aren't quite displayed right -- the other blog's title and link are missing, for instance. But at least the rest of the page is actually generated.