Inventing the wheel again? (vBulletin comment bridge)

I’ve been looking for a while for a plugin that actually synchronizes comments between vBulletin- and WordPress, but still I have not found anything that fulfills my requirements – so I’m thinking of creating such thing. But there may be a small risk that I’m inventing the wheel again. This is how I want it to work:

– You create a post on your wordpress-site. When the post are created, a thread will created on the forum.
– When comments arrive on the wP-side, the forum will be updated with the comments and when comments arrive on the vBulletin-side, comments will be updated in the blogpost.

(Sidenote – When anything updates, posts are synched). My solution differs a bit from other plugins here. Normally I’ve seen plugins where migration is more common than transparently bridging posts between the platforms. Other plugins also offers a comment system, with links to the forum, instead of using the internal functions.

So, how big is the risk, that this wheel already exists without me knowing it? ??