Why, and in what situations, would you recommend using the Event module? I can understand the situations regarding the Tk and Gtk event loops.
If Event ever becomes perl 5's standard event loop, you may want your programs to use it.
Event will let your POE-based program coexist with other modules that also require Event. This may become important if Event ever becomes perl's standard event loop.
If your program needs to handle a lot of signals, but you don't want to use Perl 5.8.0 or newer, Event may help. It polls for signals in C, allowing them to generate events without potential for coredumps.
This is not an issue in bleadperl or Perl 5.8.0. These versions of Perl include their own signal polling code, making signals safe for everyone.
Event's signal handling is also not an issue if your program only needs to handle SIGCHLD. POE includes its own code to poll for SIGCHLD without involving Perl's signal handlers.