The innovations of 5.10 has ruined three of my obfus so far (Japh algebra revisited because reading $* now gives a warning; Fun with duff's device and AUTOLOAD but that doesn't matter because it didn't really work in the first place; and One-liner japh with a completely unnecessary incompatibility). If they change smart match semantics and ruin JAPH to commemorate the release of Perl 5.10.0 too, I'll be very angry. (In reality, I think perl5's smart match is unusable, which is why I wrote that parody. Why couldn't they just copy a sane smart match semantics from ruby or perl6 or something?)