I realise we're a bit late to the party here, but we've recently been porting lots of code to the moodle 2 codebase and we wrote a tool to make the job a bit easier. Since there's still a few 1.9 modules that need converting we thought we'd make it available in case it's helpful for others too.
It was original based on the check_db_syntax script here, but we've extended it significantly, adding support for a wider range of issues, automatically fixing some common issues and a web interface. It also has some support for moving and updating language strings, help files, etc.
It's designed to be extendable, so although we haven't got rules for fixing everything yet, feel free to add more and send us pull requests to be merged.
Here it is:
https://github.com/totara/moodle2_code_converter
and here's a typical screenshot:
Enjoy!
Simon and the TotaraLMS team.