I know its been a while, but all has not been forgotten. Life has just been nuts lately. But, some progress has been made with the "softIK" solution for Maya. I came across a website from a couple years back (which makes me feel really dated) that had this ability functioning. Sadly, it was in Japanese, so all I could actually glean was the example file they sent. So my next plans are to go through the code and try to find a good way to clearly explain how the joints are being driven, and try to generate a script to automate the process. After all, that's what MEL is good for. Hopefully that update will come sooner rather than later.
In the meantime, here's a link to the site I'm basing this off of. You can download the file there as well.
Hey, I just had an ingenious idea... So, I went to the XSIBlog site (link below) and downloaded his plugin for XSI to see if I could make any sense out of it. Looks like it was written in JScript. So you should be able to open it up in a decent text editor and begin to thumb your way through it. Though I'm not familiar with JScript myself, I'm sure I can talk to some programmers at work about it and they can shed some light on the topic. More to come, but in the meantime feel free to download the plugin and see if you can make any sense out of it. It'd be a good excercise... Here's a link to the download.