Adam implemented WOFF support for Chromium last week. He discusses his thoughts on it here, so I'll direct you there for analysis.
To confirm his similarity argument, I note that the WOFF-decoding bits were implemented within the OTS project in such a way that the existing WebKit support for TrueType fonts only needed about eight lines of patch to work.
(Why push everything through OTS, rather than integrating WOFF into WebKit? Because web fonts are scary.)