"Medical Problems" will be released on March 4th.
It should be available on the official Witcher website (http://www.thewitcher.com/community/en/adventures/ ) and on my own site (http://corylea.com/).
The version available from the official Witcher website will have everything you need in one file. There will also be a version on my own site that has the movies separate from the adventure module; if you're comfortable moving files around on your hard disk (and not everybody is), the separated version should give you faster loading times than the all-in-one version.
There will be a walkthrough available on release day (though I hope you won't use it unless you really need it, since in my experience, walkthroughs take much of the fun out of games).