No, I built my own. It really doesn't do much: it can turn a QScriptValue (think that's the name -- been a while and I'm on my phone) and turns it into one of a few basic types on the .NET side, and does the inverse. It also let's you call methods on QSVs, or hook up to signals. I just built it as needed to make my FTP hack work. It's got some nice magic that allows you to find connections between QObjects, though, which is how I can get access to everything in the client just from the lobby/table window handle. Qt doesn't provide the neccesary functionality, so my framework patches and hooks a few things, e.g. signal connections.
Edit: to address the separate release part, I really don't think I'd want to do that with this. It's one of the few serious barriers to entry (the object traversal magic, specifically) that makes it non-trivial to bot the hell out of FTP. While I like poker bots and all that, it's the most valuable part of what I have, by far.
I had to do type conversion between QVariant and something similar I designed for an embedded C platform and later included in a Qt GUI. It's definitely the signal/slot traversal I found most interesting though, so I understand the desire not to release it (I'm not trying to do anything with FTP, I'm just interested in language/framework interop in general).
Edit: to address the separate release part, I really don't think I'd want to do that with this. It's one of the few serious barriers to entry (the object traversal magic, specifically) that makes it non-trivial to bot the hell out of FTP. While I like poker bots and all that, it's the most valuable part of what I have, by far.