Why upgrade to 5.8.8? First of all, the newest and shiniest release in the 5.8.x series is 5.8.9. But if you're doing major upgrade, why not skip 5.8.x and jump straight to 5.10.1? 5.10.x is actively maintained, while p5p has announced it hopes 5.8.9 will be final 5.8.x release. (In other words, if you find a bug in the perl you're using, it's more likely it gets fixed in 5.10.x than in 5.8.x).