Unfortunately, the switch from 2.7 to 3.0 is likely to be more troublesome, due mostly to the change in handling keyword arguments (they're no longer treated as equivalent to a last positional argument that happens to be a hash, and you need to toss in '*' to convert from one convention to the other). This isn't hard to clean up if you have good test coverage... but one reason for not having done upgrades is not having that.
This is a convention we've already adopted but we haven't had the chance to do a clean sweep of the rest of the codebase unfortunately. You're right though, it's one of our biggest hurdles to upgrading.
