I checked out mod_perl2 a while ago but failed to get it to install. I finished a big project at work today and decided to give it it another go, making sure to get the latest versions from CVS as the great documentation describes. Installation was very easy.
My aim was to build OpenFrame::Segment::Apache2, which is a wrapper for OpenFrame requests inside Apache 2. A fair bit of the mod_perl internals have changed, so I did find myself grepping the XS code occasionally, but basically it was all straightforward and much as for Apache 1. I used CGI::Cookie instead of Apache::Cookie. The big disappointment is that Apache::Request (which contains lots of useful functions) isn't ported to mod_perl 2 yet.
Initial benchmarking indicates that the speed is about the same (using the prefork mpm).
I would port Apache::Request myself, but I'm on a beach in Thailand for the next ten days, so see you in the new year...
